Fixes #19022

* LDAP: Allow an user to be synchronised against LDAP
This PR introduces the /ldap/sync/:id endpoint. It allows a user to be synchronized against LDAP on demand.

A few things to note are:

LDAP needs to be enabled for the sync to work
It only works against users that originally authenticated against LDAP
If the user is the Grafana admin and it needs to be disabled - it will not sync the information
Includes a tiny refactor that favours the JSONEq assertion helper instead of manually parsing JSON strings.

Adds a new requirements page to the installation docs.
Wanted/needed some place to document known browser 
issues and thought that adding this missing page together 
with OS, hardware, database and browser requirements 
would be a good thing.
Fix: move 6.4 section in upgrade notes further down.

Fixes #16487
Ref #18690

* POC: trying to see if there is a way to support objects in template interpolations

* Added support for nested objects, and arrays

* Added accessor cache

* fixed unit tests

* First take

* Use links supplier in graph

* Add field's index to cache items

* Get field index from field cache

* CHange FiledCacheItem to FieldWithIndex

* Add refId to TimeSeries class

* Make field link supplier work with _series, _field and _value vars

* use field link supplier in graph

* Fix yaxis settings

* Update dashboard schema version and add migration for data links variables

* Update snapshots

* Update build in data link variables

* FieldCache - idx -> index

* Add current query results to panel editor

* WIP Updated data links dropdown to display new variables

* Fix build

* Update variables syntac in field display, update migration

* Field links supplier: review updates

* Add data frame view and field name to TimeSeries for later inspection

* Retrieve data frame from TimeSeries when clicking on plot graph

* Use data frame's index instead of view

* Retrieve data frame by index instead of view on TimeSeries

* Update data links prism regex

* Fix typecheck

* Add value variables to suggestions list

* UI update

* Rename field to config in DisplayProcessorOptions

* Proces single value of a field instead of entire data frame

* Updated font size from 10px to 12px for auto complete

* Replace fieldName with fieldIndex in TimeSeries

* Don't use .entries() for iterating in field cache

* Don't use FieldCache when retrieving field for datalinks in graph

* Add value calculation variable to data links (#19031)

* Add support for labels with dots in the name (#19033)

* Docs update

* Use field name instead of removed series.fieldName

* Add test dashboard

* Typos fix

* Make visualization tab subscribe to query results

* Added tags to dashboard so it shows up in lists

* minor docs fix

* Update singlestat-ish variables suggestions to contain series variables

* Decrease suggestions update debounce

* Enable whitespace characters(new line, space) in links and strip them when processing the data link

* minor data links UI update

* DataLinks: Add __from and __to variables suggestions to data links (#19093)

* Add from and to variables suggestions to data links

* Update docs

* UI update and added info text

* Change ESC global bind to bind (doesn't capture ESC on input)

* Close datalinks suggestions on ESC

* Remove unnecessary fragment

* Singlestat: fix format messes up on negative values if select duration (hh:mm:ss) unit

* Added test for 0

* Add more alignment period options

* Remove unnecessary alignment period limit

* QueryProcessing: Added missing error event for angular editors

* fix if else

* don't listen to legacy data events in graph

* fix test

* rename function

* add annotationsSrv stub

* use const

* fix preProcessPanelData

* update test

* PanelQueryRunner: Need to cache preProcessPanelData function between runs so last result can be remembered

* Better fix for remembering lastResult

* Code simplification

* Simplify code a bit

Allow api to accept inviting existing users when login form is disabled.
UI shows invite button when login form is disabled.

* fix for #19049

Minor grammar edits. Mostly added periods and colons. 
Made heading capitalization consistent.

Added punctuation and made minor grammar and format edits. 
Mostly added periods and colons.

* I needed to learn some rxjs and understand this more, so just playing around

* Updated

* Removed all the complete calls

* Refactoring

* StreamHandler -> observable start

* progress

* simple singal works

* Handle update time range

* added error handling

* wrap old function

* minor changes

* handle data format in the subscribe function

* Use replay subject to return last value to subscribers

* Set loading state after no response in 50ms

* added missing file

* updated comment

* Added cancelation of network requests

* runRequest: Added unit test scenario framework

* Progress on tests

* minor refactor of unit tests

* updated test

* removed some old code

* Shared queries work again, and also became so much simplier

* unified query and observe methods

* implict any fix

* Fixed closed subject issue

* removed comment

* Use last returned data for loading state

* WIP: Explore to runRequest makover step1

* Minor progress

* Minor progress on explore and runRequest

* minor progress

* Things are starting to work in explore

* Updated prometheus to use new observable query response, greatly simplified code

* Revert refId change

* Found better solution for key/refId/requestId problem

* use observable with loki

* tests compile

* fix loki query prep

* Explore: correct first response handling

* Refactorings

* Refactoring

* Explore: Fixes LoadingState and GraphResults between runs (#18986)

* Refactor: Adds state to DataQueryResponse

* Fix: Fixes so we do not empty results before new data arrives
Fixes: #17409

* Transformations work

* observable test data

* remove single() from loki promise

* Fixed comment

* Explore: Fixes failing Loki and Prometheus unit tests (#18995)

* Tests: Makes datasource tests work again

* Fix: Fixes loki datasource so highligthing works

* Chore: Runs Prettier

* Fixed query runner tests

* Delay loading state indication to 200ms

* Fixed test

* fixed unit tests

* Clear cached calcs

* Fixed bug getProcesedDataFrames

* Fix the correct test is a better idea

* Fix: Fixes so queries in Explore are only run if Graph/Table is shown (#19000)

* Fix: Fixes so queries in Explore are only run if Graph/Table is shown
Fixes: #18618

* Refactor: Removes unnecessary condition

* PanelData: provide legacy data only when needed  (#19018)

* no legacy

* invert logic... now compiles

* merge getQueryResponseData and getDataRaw

* update comment about query editor

* use single getData() function

* only send legacy when it is used in explore

* pre process rather than post process

* pre process rather than post process

* Minor refactoring

* Add missing tags to test datasource response

* MixedDatasource: Adds query observable pattern to MixedDatasource (#19037)

* start mixed datasource

* Refactor: Refactors into observable parttern

* Tests: Fixes tests

* Tests: Removes console.log

* Refactor: Adds unique requestId

- upgraded rc-cascader (did not fix the alignment issue)
- Safari seems to default to middle alignment, added override to explore
styles
- added empty expand icon property to satisfy API after upgrade

* API: Add `updatedAt` to api/users/:id

This adds the timestamp of when a particular user was last updated to
the `api/users/:id` endpoint.

This helps our administrators understand when was the user information last
updated. Particularly when it comes from external systems e.g. LDAP

* Adding DashboardPicker component

* fix prop names

* fix prop names pt2

* add component and modify utils

* add showHour prop

* add minuteStep to TimeOfDayPicker, add value to DashboardPicker

* fix for dashboard picker, missed adding file

* Adding story

* add another story for hiding hour and style fixes

* fix these generated files

* fixes after review

* rename current value

* fix type issue on onChange

* fix story

* update maxDataPoints UI

* use maxDataPoints to calculate interval

* don't change interval calculation

this way importing the tsdb package does not come with xorm dependencies

* Adding T and P for bytes

Luckily, all the hard work was done before; just added in these prefixes for our production environment.

* Future-proofing with other values (why not?)

* Yottaflops?

* Cutting back down to Peta sizes, except for hashes