* Explore: facetting for label completion

- unified metric and non-metric label completion
- label keys and values are now fetched fresh for each valid selector
- complete selector means only values are suggested that are supported
  by the selector
- properly implemented metric lookup for selectors (until the first
  metric was used which breaks when multiple metrics are present)
- typeahead tests now need a valid selection to demark the cursor

* Fix facetting queries for empty selector

Karma to Jest: variable_srv

Karma to Jest: OpenTSDB datasource

Karma to Jest: remove tests

* Add click on explore table cell to add filter to query

- move query state from query row to explore container to be able to set
  modified queries
- added TS interface for columns in table model
- plumbing from table cell click to datasource
- add modifyQuery to prometheus datasource
- implement addFilter as addLabelToQuery with tests

* Review feedback

- using airbnb style for Cell declaration
- fixed addLabelToQuery for complex label values

[skip ci]

Add auto_assign_org_id to defaults.ini

For #12801

[skip ci]

[skip ci]

remove alias from postgres $__timeGroup macro

add $__timeGroupAlias macro to all sql datasources

table link color fix

[skip ci]

Add new Redshift metrics and dimensions for Cloudwatch datasource

 AWS/Redshift has new dimensions (`latency`, `service class`, `wmlid`) and metrics (`QueriesCompletedPerSecond`, `QueryRuntimeBreakdown`, `QueryDuration`,  `WLMQueriesCompletedPerSecond`, `WLMQueryDuration`, `WLMQueueLength`) in Cloudwatch: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/rs-metricscollected.html

[skip ci]

[skip ci]

* Improve iOS homescreen icon

* Improve Windows10 tile experience

* Remove unused favicon

* add series override option to hide tooltip

* fix test

* invert option

* fix test

* remove initialization

[skip ci]

fix custom variable quoting in sql* query interpolations

Karma to Jest: prometheus datasource