Google Cloud service accounts use a JWT token to get an
oauth access token. This adds support for that.

fix: use datasource cache for backend datasources

Fix anonymous usage stats for authentication types

[metrics]enabled = false should disable the /metrics endpoint.

Just wanted to reduce the amount of files/folders in root

[skip ci]

(prometheus) add annotation option to treat series value as timestamp 

add support for interpolate $__interval and  $__interval_ms in sql datasources

but we will still keep sending metrics to graphite

closes #10638

* creating types, actions, reducer

* load teams and store in redux

* delete team

* set search query action and tests

* Teampages page

* team members, bug in fetching team

* flattened team state, tests for TeamMembers

* test for team member selector

* wip: began folder to redux migration

* team settings

* actions for group sync

* wip: progress on redux folder store

* wip: folder to redux

* wip: folder settings page to redux progress

* mobx -> redux: major progress on folder migration

* redux: moved folders to it's own features folder

* fix: added loading nav states

* fix: gofmt issues

* wip: working on reducer test

* fix: added reducer test

(prometheus) get label name/value from series API 

* Basic adhoc-filtering support for prometheus