Remove `approval_rules` feature flag and remove obsolete approvals implementation

Closes #10685

See merge request gitlab-org/gitlab-ee!12436

Cancel auto merge when merge request is closed

See merge request gitlab-org/gitlab-ce!28782

Resolve "Use GitLab serverless with existing Knative installation"

Closes #58941

See merge request gitlab-org/gitlab-ce!27173

Port of Use GitLab serverless with existing Knative installation to EE

See merge request gitlab-org/gitlab-ee!11589

Remove Kn services cache from Clusters::Application::Knative

Knative function can exist even if user did not installed Knative via
GitLab managed apps.

-> Move responsibility of finding services into the Cluster
-> Responsability is inside Clusters::Cluster::KnativeServiceFinder
-> Projects::Serverless::FunctionsFinder now calls depends solely on a
cluster to find the Kn services.
-> Detect Knative by resource presence instead of service presence
-> Mock knative_installed response temporarily for frontend to develop

Display loader while `installed === 'checking'`

Added frontend work to determine if Knative is installed

Memoize with_reactive_cache(*args, &block) to avoid race conditions

When calling with_reactive_cache more than once, it's possible that the
second call will already have the value populated. Therefore, in cases
where we need the sequential calls to have consistent results, we'd fall
under a race condition.

Check knative installation via Knative resource presence

Only load pods if Knative is discovered

Always return a response in FunctionsController#index

- Always indicate if Knative is installed, not installed or checking
- Always indicate the partial response for functions. Final response is
guaranteed when knative_installed is either true | false.

Adds specs for Clusters::Cluster#knative_services_finder

Fix method name when calling on specs

Add an explicit check for functions

Added an explicit check to see if there are any functions available

Fix Serverless feature spec

- we don't find knative installation via database anymore,
rather via Knative resource

Display error message for request timeouts

Display an error message if the request times out

Adds feature specs for when functions exist

Remove a test purposed hardcoded flag

Add ability to partially load functions

Added the ability to partially load functions on the frontend

Add frontend unit tests

Added tests for the new frontend additions

Generate new translations

Generated new frontend translations

Address review comments

Cleaned up the frontend unit test.
Added computed prop for `isInstalled`.

Move string to constant

Simplify nil to array conversion

Put knative_installed states in a frozen hash for better read

Pluralize list of Knative states

Quey services and pods filtering name

This way we don't need to filter the namespace in memory.
Also, the data we get from the network is much smaller.

Simplify cache_key and fix bug

- Simplifies the cache_key by removing namespace duplicate
- Fixes a bug with reactive_cache memoization

Introduce sidekiq worker for auto merge process

See merge request gitlab-org/gitlab-ce!28780

Extract strings to gettext

Closes #61960

See merge request gitlab-org/gitlab-ce!28489

There are no namespaces in the strings so we don't need those

Port of 61960-translatable-strings-in-issue-closure-emails to EE

Closes gitlab-ce#61960

See merge request gitlab-org/gitlab-ee!13219

There are no namespaces in the strings so we don't need those

Add index to count pending mirror updates

Closes gitlab-ce#62419

See merge request gitlab-org/gitlab-ee!13901

De-quarantine e2e test for issue suggestions

Closes gitlab-org/quality/staging#53

See merge request gitlab-org/gitlab-ce!29046

Add endpoint to regenerate feature flags client token

See merge request gitlab-org/gitlab-ee!13450

Request:
```
POST /*namespace_id/:project_id/-/feature_flags_client/reset_token
```

Response:
```
{
  "token" => "new-token-value"
}
```

Ignore Puma empty worker stats

See merge request gitlab-org/gitlab-ce!28932

In some cases (during worker start) it's possible that
Puma.stats returns an empty hash for worker's last status. In
that case we just skip sampling of the worker until these
stats are available.

Resolve "Docs feedback: unstage page needs clarification"

Closes #62618

See merge request gitlab-org/gitlab-ce!29113

Fixes some Phabricator import docs problems

See merge request gitlab-org/gitlab-ce!29114

Onboarding Welcome page: leverage onboarding utils and popover components

See merge request gitlab-org/gitlab-ee!13370

Make pipeline schedule worker resilient

Closes gitlab-com/gl-infra/production#805 and #61955

See merge request gitlab-org/gitlab-ce!28407

Add Dependency List table and row components

See merge request gitlab-org/gitlab-ee!13670

Resolve EE/CE differences in app/views/profiles/keys

See merge request gitlab-org/gitlab-ce!28900

Resolve EE differences in app/views/profiles/keys

Closes #6227 and #10506

See merge request gitlab-org/gitlab-ee!13575

Use global isSafeURL utility in safe_link component

See merge request gitlab-org/gitlab-ee!13926

Add expand/collapse button to operation settings

Closes #61511

See merge request gitlab-org/gitlab-ce!28840

Add ability to expand/collapse operation settings