Refactor setting fillmode

Originally from the grafana/grafana-docker repo, authored
by @ClementGautier.

Fixes #12882

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

This adds SetupFillmode to the tsdb package to be used by the sql
datasources.

Convert URL-like text to links in plugins readme

Add example OR search_filter to docs

Delete button for team members page 

Explore: expand recording rules for queries

This Dockerfile allows anyone with a recent version of Docker to quickly build a fully working Grafana container without any local build tooling. Pulling the sources from Git and calling `docker build .` is enough.

- load recording rules from prometheus
- map rule name to rule query
- query hint to detect recording rules in query
- click on hint fix expands rule name to query

* Explore: Query hints for prometheus

- time series are analyzed on response
- hints are shown per query
- some hints have fixes
- fix rendered as link after hint
- click on fix executes the fix action

* Added tests for determineQueryHints()

* Fix index for rate hints in explore

[skip ci]

Add fill mode to fill in previously seen value when point is missing to SQL datasources

Fixing bug in url query reader and added test cases

[skip ci]

Fix issue with secret fields after updating datasource

fix missing *

The missing * causes the text to be in the box to be displayed incorrectly.

Explore: prometheus query helpers 

- use color variables for cascader styles
- fix Table value type