Migrate Gitlab::Git::Repository#add_tag to Gitaly

Closes gitaly#601

See merge request gitlab-org/gitlab-ce!14500

Closes gitaly#601

Migrate Git::Repository#rm_tag to Gitaly

Closes gitaly#562

See merge request gitlab-org/gitlab-ce!14388

Closes gitaly#562

RepoEditor: Prevent extra network call for already opened files.

Closes #38256

See merge request gitlab-org/gitlab-ce!14489

Docs: Feature overview and use cases

Closes #38076

See merge request gitlab-org/gitlab-ce!14538

Docs: crosslink Pages guides

Closes #38427

See merge request gitlab-org/gitlab-ce!14542

Clear merge requests counter cache after merge

Closes gitlab-ee#3573 and #38344

See merge request gitlab-org/gitlab-ce!14563

Hashed storage migration path

Closes gitlab-ee#3118

See merge request gitlab-org/gitlab-ce!14067

Use relative paths for opening and closing issuables

Closes #35822

See merge request gitlab-org/gitlab-ce!14555

Support custom attributes on users

See merge request gitlab-org/gitlab-ce!13038

Document the usage of the Docker OverlayFS driver for every build

See merge request gitlab-org/gitlab-ce!14478

Before this change, the MR counter in the sidebar would be wrong if an MR had
been merged since the last update, but not opened or closed, as merging did not
trigger a counter cache update.

Changed account confirmation line to e-mail text.

Closes #13637

See merge request gitlab-org/gitlab-ce!14243

Fix spelling of occurred

See merge request gitlab-org/gitlab-ce!14488

Make sure API responds with 401 when invalid authentication info is provided

Closes #38438

See merge request gitlab-org/gitlab-ce!14525

Test for what should not be there as well

[ci skip]

See merge request gitlab-org/gitlab-ce!14492

Resolve "NoMethodError: undefined method `sha' for nil:NilClass"

Closes #38319

See merge request gitlab-org/gitlab-ce!14547

The abuse reports need a full issuable URL, but linking to issuables
should use the relative paths

This is used in EE for the storage migration, and we want to use this
in CE as well to be able to migrate projects to hashed_storage.

Clarify artifact download via the API only accepts branch or tag name for ref

See merge request gitlab-org/gitlab-ce!14545

Fixed missing namespaces on navigation translations

See merge request gitlab-org/gitlab-ce!14472

Lazy load images in mobile sidebar & header

Closes #38276

See merge request gitlab-org/gitlab-ce!14526

Fixes commit comments in parallel diff view

Closes #38117

See merge request gitlab-org/gitlab-ce!14529

If the ref doesn't exist, and the source branch is deleted, we can't get it back
easily. Previously, we ignored this error by shelling out, so replicate that
behaviour.

RepositoryExists is always called with #gitaly_migration

Closes #38333

See merge request gitlab-org/gitlab-ce!14513

Refactor services to match EE signature

See merge request gitlab-org/gitlab-ce!14385

Clean merge_jid whenever necessary on the merge process

Closes #38476

See merge request gitlab-org/gitlab-ce!14540