Hide admin Audit Log in sidebar when not licensed

Closes #3197

See merge request !2726

Removes Gitlab::Metrics usage from StuckImportJobsWorker

See merge request !2728

Hijack ActiveRecord::Base.connection in the DB load balancer

Closes #3191

See merge request !2707

Only show the Audit Log in the Admin sidebar when the installation has
a valid EE license to use that feature.

[EE] Greatly reduce test duration for git_access_spec

See merge request !2719

fix Modify commit message button spacing

Closes #3163

See merge request !2693

Fixes Audit Events Documentation issue link

See merge request !2725

Refactor GPG docs

See merge request !2724

Fix url for object store artifacts

Closes #3172

See merge request !2705

1. Generating a GPG key
1. Signing commits
1. Associating a GPG key with Git

- Reduces duplication of long ref strings
- Passes push rule attributes directly to `create_push_rule`, rather
  than creating one and then updating it.

Due to a logic error, these specs weren't actually doing anything -- we
were running the checks on `Hash.new(Hash.new(false))`, which is just
`{}`.

Make issuable filter dropdown style consistent

See merge request !2711

This uses the same thinking as the earlier `run_permission_checks`
refactor, to run all of the checks for the matrix in a single `it` block
to avoid repeated setup.

- Adds a new `ProjectMovedError` class to encapsulate that error
  condition. Inherits from `NotFoundError` so existing rescues should
  continue to work.
- Separating that condition out of `NotFoundError` allowed us to
  simplify the `raise_not_found` helper and avoid repeating the literal
  string.
- Spec makes use of `ERROR_MESSAGES` hash to avoid repeating literal
  error message strings.

- Combine multiple `it` blocks into one where it made sense
- Use `set` for the top-level User record
- Refactor permission matrix tests

This changes the load balancing logic so we hijack
`ActiveRecord::Base.connection` instead of hijacking "connection" on a
per model basis. This ensures _all_ code that might use it (including
Rails internals) goes through the database load balancer. This in turn
should make the application more resistant to failures on the primary.

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/3191

Resolve "Export issue time tracking information"

Closes #1406

See merge request !2627

Document how to use AWS IAM profiles for object storage

See merge request !2708

Tuesday: CE upstream

Closes #3178, #2750, gitaly#404, and gitlab-ce#27390

See merge request !2683

[ci skip]

Move workflow/importing/ to user/project/import/

See merge request !2694

Fixed issue boards focus mode not being visible to guest users

Closes #3182

See merge request !2699

Fix LDAP backwards compatibility

Closes gitlab-ce#36432 and #3082

See merge request !2690

Closes #3182

Fix pipeline quota text not collapsing in the new sidebar

See merge request !2697