Fixes #17665

This commit addresses half of #13749 by making sure GetMetricData 
works for alerting. Math Expressions (compound metrics) will still not 
work for alerting, this would require a bigger refactoring of Grafana's 
alerting service. However, with this commit at least alerting for basic 
metrics with non empty query Id will work.

Fixes half of #13749

* CI: Added metric to track strict null errros

* Update scripts/ci-frontend-metrics.sh

Co-Authored-By: Hugo Häggmark <hugo.haggmark@grafana.com>

* Auth: Do not search for the user twice

Previously `initContextWithBasicAuth` did not use `LoginUserQuery`, doing
`GetUserByLoginQuery` only i.e. looking user in DB only, things changed when
this function started to check LDAP provider via `LoginUserQuery` (#6940),
however, this request was placed after `GetUserByLoginQuery`, so we first
looking in DB then in the LDAP - if LDAP user hasn't logged in we will
not find it in DB, so `LoginUserQuery` will never be reached.

`LoginUserQuery` request already performs `GetUserByLoginQuery`
request in correct sequence. So we can just remove redundant request.

* Correct sequence execution during authentification &
  introduce tests for it

* Move basic auth tests to separate test file, since main test file already
  pretty large

* Introduce `testing.go` for the middleware module

* Remove redundant test helper function

* Make handler names more explicit

Ref 5777f65d
Fixes #18329

* Auth: address review comment

* added alert rule tags in webhook notifications

* fix: don't include whole list of Tag objects but only key/value pairs in Webhook JSON

* marked webhook alerts to support alert rule tags

* Changelog: v6.3.0-beta3

* Changelog: 6.3.0-beta4

* UI: Fixes issue where ToggleButtonGroup overlapped DataSourcePicker in Firefox
Closes #17692

* Select: added more padding to right to make space for indicator/caret

* Connect SignIn with redux and get url

* Update test snapshot

* Add tests for errors basic auth cases and moves tests to separate test-case.
Also names test cases consistently

* Add additional test helper

Ref 82661b9f

* LDAP: nitpicks

* Add more tests

* Correct and clarify comment for Login() method

* Rename methods (hail consistency!)

* Uppercases first letter of the logs everywhere

* Moves method definitions around to more appropriate places

Fixes #18295

Ref #17771
Fixes #18106

If wildcards are in the quotes they not going to be expanded

* Auth: consistently return same basic auth errors

* Put repeated errors in consts and return only those consts as error strings

* Add tests for errors basic auth cases and moves tests to separate test-case.
  Also names test cases consistently

* Add more error logs and makes their messages consistent

* A bit of code style

* Add additional test helper

* Auth: do not expose even incorrect password

* Auth: address review comments

Use `Debug` for the cases when it's an user error

Closes #18037

Create and push the expected tag to grafana-dev repository
and use this instead for running the end to end tests
for the release.

The `oauth_state` cookie used to be created with the SameSite value set
according to the `cookie_samesite` configuration.
However, due to a Safari bug SameSite=None or SameSite=invalid are treated
as Strict which results in "missing saved state" OAuth login failures
because the cookie is not sent with the redirect requests to the OAuth
provider.
This commit always creates the `oauth_state` cookie with SameSite=Lax
to compensate for this.

* Add types and rewrite datasourceChanged to async/await

Closes #18159

* Imperative mood

The English language suggests that when giving out instructions or considerations is best to use imperative mood as the writing style. Done as part of this commit:

- some worth smithing to match this style
- changed the format to match the fact that this is commonly read as part of a text box when opening up your PRs
- and extended a few descriptions to make it more friendly for newcomers