Storing queries, split state, and time range in URL.

- harmonize query serialization when generating Explore URLs in
  dashboards (use of `renderUrl`)
- move URL parse/serialization to Wrapper
- keep UI states under two keys, one for left and one for right Explore
- add option to angular router to not reload page on search change
- add lots of types
- fix time service function that gets triggered by URL change

Adding AWS Isolated Regions

Plugin list to react

Compile TS on precommit hook

- was not covered by TS lint
- TS errors are only noticed in broken builds
- added grunt task to run `tsc --noEmit`

Merge branch 'text_variable-3173' of https://github.com/daldoyle/grafana into daldoyle-text_variable-3173

fixes to dark theme for Explore mode

switch button for org users

resolve symlink on each run

Prevent refresh on fixed time window

Add goconst to CircleCI

Fix goconst issues

imguploader: Add support for ECS credential provider for S3

filter NULL values in column value suggestion query

alerting: move all notification conditions to defaultShouldNotify

Remove .dropdown-menu-open on body click fixes #13409

provisioning: changed update interval default 3 to 10 seconds