Add a license check for group-webhooks

Closes #2576

See merge request !2280

Fix spec failure for squash in progress error handling

See merge request !2343

Fixed admin sidebar not showing all options in new navigation

See merge request !2334

Port of 32838-admin-panel-spacing to EE

See merge request !2264

Show loading icon when retrieving Geo node status

Closes #1977

See merge request !2309

Resolve EE conflicts for "Fix API Scoping"

See merge request !2338

Similar to how we check project features.

- Hide the `webhooks` link from the group-settings page
- All group-webhooks-pages render a 404
- Don't execute webhooks if the feature is disabled

EE Port: Honor the "Remember me" parameter for OAuth-based login

See merge request !2175

- There were conflicting changes in `master` that were fixed in
  94258a65. This made rebasing the commits from gitlab-ce!12300
  problematic, due to conflicts.

- Instead, I squashed all !12300 commits into a single commit, and
  cherry-picked that onto 33580-fix-api-scoping-ee, which resulted
  in this commit.

Original commit messages below
==============================

Initial attempt at refactoring API scope declarations.

- Declaring an endpoint's scopes in a `before` block has proved to be
  unreliable. For example, if we're accessing the `API::Users` endpoint - code
  in a `before` block in `API::API` wouldn't be able to see the scopes set in
  `API::Users` since the `API::API` `before` block runs first.

- This commit moves these declarations to the class level, since they don't need
  to change once set.

Allow API scope declarations to be applied conditionally.

- Scope declarations of the form:

    allow_access_with_scope :read_user, if: -> (request) { request.get? }

  will only apply for `GET` requests

- Add a negative test to a `POST` endpoint in the `users` API to test this. Also
  test for this case in the `AccessTokenValidationService` unit tests.

Test `/users` endpoints for the `read_user` scope.

- Test `GET` endpoints to check that the scope is allowed.
- Test `POST` endpoints to check that the scope is disallowed.
- Test both `v3` and `v4` endpoints.

When verifying scopes, manually include scopes from `API::API`.

- They are not included automatically since `API::Users` does not inherit from
  `API::API`, as I initially assumed.

- Scopes declared in `API::API` are considered global (to the API), and need to
  be included in all cases.

Test OAuth token scope verification in the `API::Users` endpoint

Add CHANGELOG entry for CE MR 12300

Fix remaining spec failures for !12300.

1. Get the spec for `lib/gitlab/auth.rb` passing.

  - Make the `request` argument to `AccessTokenValidationService` optional -
  `auth.rb` doesn't need to pass in a request.

  - Pass in scopes in the format `[{ name: 'api' }]` rather than `['api']`, which
  is what `AccessTokenValidationService` now expects.

2. Get the spec for `API::V3::Users` passing

2. Get the spec for `AccessTokenValidationService` passing

Implement review comments from @dbalexandre for !12300.

Implement review comments from @DouweM for !12300.

- Use a struct for scopes, so we can call `scope.if` instead of `scope[:if]`

- Refactor the "remove scopes whose :if condition returns false" logic to use a
  `select` rather than a `reject`.

Extract a `Gitlab::Scope` class.

- To represent an authorization scope, such as `api` or `read_user`
- This is a better abstraction than the hash we were previously using.

`AccessTokenValidationService` accepts `String` or `API::Scope` scopes.

- There's no need to use `API::Scope` for scopes that don't have `if`
  conditions, such as in `lib/gitlab/auth.rb`.

Fix build for !12300.

- The `/users` and `/users/:id` APIs are now accessible without
  authentication (!12445), and so scopes are not relevant for these endpoints.

- Previously, we were testing our scope declaration against these two methods.
  This commit moves these tests to other `GET` user endpoints which still
  require authentication.

Check license for milestones on issue boards

Closes #2568

See merge request !2315

Introduce namespace license checks for Push Rules (EES)

Closes #2573

See merge request !2335

Clarify when Code Quality shows in MR widget

Closes #2782

See merge request !2298

Namespace license checks Issue & MR template

Closes #2580

See merge request !2321

And separate EE/CE for board.rb

Introduce namespace license checks for merge request approvers (EES)

Closes #2566

See merge request !2324

# Conflicts:
#   app/models/license.rb

Hide Focus mode button if feature not available in license

Closes #2569

See merge request !2303

Namespace license checks for Contribution Analytics (EES)

Closes #2579

See merge request !2302

Fix EE conflicts for "Allow unauthenticated access to the `/api/v4/users` API"

See merge request !2247

When the Issuable Default Template feature is not available, do not
show the input form to configure the Issue & MR templates on the
Settings page.

Only when the Issuable Default Templates feature is available, fill in
the description from settings when building a new MR.