Make Gitaly signature RPC's mandatory

Closes gitaly#745, gitaly#1044, and gitaly#876

See merge request gitlab-org/gitlab-ce!20212

Make Gitaly search and message RPC's mandatory

Closes gitaly#1202, gitaly#1201, gitaly#1199, gitaly#1198, and gitaly#951

See merge request gitlab-org/gitlab-ce!20210

Update integrations external link icons

See merge request gitlab-org/gitlab-ce!20205

Update environments nav controls icons

See merge request gitlab-org/gitlab-ce!20199

Add extra logging to githost.log when rebasing

See merge request gitlab-org/gitlab-ce!20202

Add SHA256 and HEAD on File API

See merge request gitlab-org/gitlab-ce!19439

Mark MR as merged regardless of errors when closing issues

See merge request gitlab-org/gitlab-ce!20218

Correct "autorize" typos

See merge request gitlab-org/gitlab-ce!20225

Fix spelling: Uncommment -> Uncomment

[ci skip]

See merge request gitlab-org/gitlab-ce!20226

Componentize diff lines and diff comments

Closes #48297

See merge request gitlab-org/gitlab-ce!19702

Run repository checks parallel for each shard

Closes #48042

See merge request gitlab-org/gitlab-ce!20179

There is only 1 `HEALTHY_SHARD_CHECKS` used:
Gitlab::HealthChecks::GitalyCheck

So we can simplify code to get the list of healthy shard names.

The RepositoryCheck::DispatchWorker will start a
RepositoryCheck::BatchWorker for each healthy shard.

Closes gitlab-org/gitlab-ce#48042

It already existed in EE in the Geo namespace. This change brings it
to CE.

Migrate storage nesting check to Gitaly

Closes gitaly#1237

See merge request gitlab-org/gitlab-ce!20208

Improve Hashed Storage documentation for rollback

See merge request gitlab-org/gitlab-ce!20203

We should mark the MR as merged as first thing on PostMergeService as in practice it is already merged on the repository. Happens that errors may happen when executing external services such as Issues::CloseService, and we do not want a MR hanging as opened because of that.

Moves boards components into a .vue file

See merge request gitlab-org/gitlab-ce!20177

Updates exception request documentation to link to the new location

See merge request gitlab-org/gitlab-ce!20207

Gitaly metrics check for read/writeability

Closes gitaly#1218

See merge request gitlab-org/gitlab-ce!20022

Resolve "`!` autocomplete does not work anymore"

Closes #48528

See merge request gitlab-org/gitlab-ce!20204

Enable frozen string for app/workers/**/*.rb

See merge request gitlab-org/gitlab-ce!20197

Merge branch '46546-do-not-pre-select-previous-user-s-when-creating-protected-branches' into 'master'

CE port gitlab-ee!6112

Closes #46546

See merge request gitlab-org/gitlab-ce!19714

Fixed storage coverage table with additional information
and wrote down implementationd details from few entities.

CE-EE parity for spec/models

See merge request gitlab-org/gitlab-ce!20165