Adds a new "Image Rendering" page in Administration section.
Updates configuration page with rendering settings and also 
default.ini and sample.ini.
Updates and cleanup pages that referencing image rendering.

Ref #18914

* Updated whats new article

* Fixed reports image

* fixes to whats new doc

* Minor changes

This reverts commit 601853fc.

* Chore: Update Slate to 0.47.8
Closes #17430

* Add slate and immutable to grafana-ui deps

* Fixes some small regressions introduced

* Fix suggestions for multiple query fields

* Pin upgraded dependencies

* Prettier fix

* Remove original slate-react dependency

* Fix tiny-invariant dep

* (Temporarily) comments out source maps for grafana-ui

Breaking changes and deprecation notes for v6.4

Closes #18520

Co-Authored-By: Dominik Prokop <dominik.prokop@grafana.com>

* What's new 6.4 draft

* data model notes

* minor progress

* Only include top highlights list

* Add new query mode picker with different states for each query. Also really simple migration script

* Populate cross resource dropdowns

* Cleanup. Handle change events

* Add multi select picker for subscriptions

* Fix markup issue

* Prepare for new query mode

* More cleanup

* Handle multiple queries both in ds and backend

* Refactoring

* Improve migration

* Add support for multiselect display name

* Use multiselect also for locations and resources

* Add more typings

* Fix migrations

* Custom multiselect built for array of options instead of variables

* Add url builder test

* fix datasource tests

* UI fixes

* Improve query editor init

* Fix brokens tests

* Cleanup

* Fix tslint issue

* Change query mode display name

* Make sure alerting works for single queries

* Friendly error for multi resources

* Add temporary typings

* Readonly datasources should not be created via the API

* Return correct `ReadOnly` value in GetDataSourceByName

* LDAP: add nav link only if ldap enabled

* LDAP: /admin/ldap required admin permissions

Fixes: #18531

* Feature: Encapsulated dynamic imports with error boundary and suspense

* Refactor: Changes after PR review

* Align PageLoader and LoadingPlaceholder

* Updated loading failed UI abit

* Change Failed to Unable

Don't update total stats metrics if reporting is disabled.
New setting disable_total_stats for turning off update 
of total stats (stat_totals_*) metrics.

Ref #19137

* Organise data frame and vectors code

* Organise transformations

* Move dataframe utils to dataframe dir

* Organise datetime utils

* Organise text utils

* Organise logs utils

* Revert "Organise logs utils"

This reverts commit c24115c75558236770dfa2f151e81f71bcd9ddef.

* registry -> Registry

* Transformations reorg

* Explore: add no data points text to graph

* Explore: add console log for error (accidentaly removed)

* Explore: refactor, created getYAxes method for better readability

* Explore: remove unnecessary console.log

* Explore: fix getYAxes method to return value

* Graph: Simplify warning from no data points to No data

* Add items for navmodel and basic page

* add reducer and actions

* adding user mapping table component

* adding components for ldap tables

* add alert box on error

* close error alert box

* LDAP status page: connect APIs WIP

* LDAP debug: fetch connection status from API

* LDAP debug: fetch user info from API

* LDAP debug: improve connection error view

* LDAP debug: connection error tweaks

* LDAP debug: fix role mapping view

* LDAP debug: role mapping view tweaks

* LDAP debug: add bulk-sync button stub

* LDAP debug: minor refactor

* LDAP debug: show user teams

* LDAP debug: user info refactor

* LDAP debug: initial user page

* LDAP debug: minor refactor, remove unused angular wrapper

* LDAP debug: add sessions to user page

* LDAP debug: tweak user page

* LDAP debug: tweak view for disabled user

* LDAP debug: get sync info from API

* LDAP debug: user sync info

* LDAP debug: sync user button

* LDAP debug: clear error on page load

* LDAP debug: add user last sync info

* LDAP debug: actions refactor

* LDAP debug: roles and teams style tweaks

* Pass showAttributeMapping to LdapUserTeams

* LDAP debug: hide bulk sync button

* LDAP debug: refactor sessions component

* LDAP debug: fix loading user sessions

* LDAP debug: hide sync user button

* LDAP debug: fix fetching unavailable /ldap-sync-status endpoint

* LDAP debug: revert accidentally added fix

* LDAP debug: show error when LDAP is not enabled

* LDAP debug: refactor, move ldap components into ldap/ folder

* LDAP debug: styles refactoring

* LDAP debug: ldap reducer tests

* LDAP debug: ldap user reducer tests

* LDAP debug: fix connection error placement

* Text update

* LdapUser: Minor UI changes moving things around

* AlertBox: Removed icon-on-top as everywhere else it is centered, want to have it be consistent

* Elasticsearch Datasource: allow templating queries to order by doc_count

* Elasticsearch Datasource: add tests for doc_count templating queries

* Bump lodash to 4.17.15

* Bump pretty-format to 24.9.0

Fixes: #19114

* Update routing to require sign in on every route

* Review update

* Graph: constant series as override

- ability to define a series override that takes the first value of a
timeseries and produces constant series from it.

* Moved constant series override logic to grafana-ui

* Added docs for instant queries and constant series override

* DataFrame: Fixes to dealing with empty results

* review feedback fixes

* Explore: calculate intervals when building data source request

* Added unit test

* updated unit test

* Refactor: Renamed and changed Signature for OnHorizontalRegionSelected

* Refactor: Adds onHorizontalRegionSelected to GraphPanelController

* Refactor: Moves TimeSrv call to PanelChrome instead

* Loki: Updated cheat sheet with new filter syntax

- updated cheat sheet with new filter syntax
- added user-specific examples from the user's label set
- added link to LogQL docs
- separated styles for examples (clickable) and expressions

* Review feedback

* Find correct module files

* Add basic error tracing

* Add delete button to edit notification channel page

* Simplified code