Fix 500 errors with legacy appearance logos

Closes #9357

See merge request gitlab-org/gitlab-ee!9277

Prior to GitLab 9.0, attachments were not tracked the `uploads` table,
so it was possible that the appearance logos were just stored in the
database as a string and mounted via CarrierWave.

https://gitlab.com/gitlab-org/gitlab-ce/issues/29240 implemented in
GitLab 10.3 was supposed to cover populating the `uploads` table for all
attachments, including all the logos from appearances. However, it's
possible that didn't work for logos or the `uploads` entry was orphaned.

GitLab instances that had a customized logo with no associated `uploads`
entry would see Error 500s. The only way to fix this is to delete the
`logo` column from the `appearances` table and re-upload the attachment.

This change makes things more robust by falling back to the original
behavior if the upload is not available.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/9357

[API] Omit `X-Total` and `X-Total-Pages` headers when items count is more than 10,000

Closes #42194 and #52674

See merge request gitlab-org/gitlab-ce!23931

Update ee gitlab.pot

Closes #9359

See merge request gitlab-org/gitlab-ee!9276

documentation: Add `git clone` to list of basic git commands

Closes #56514

See merge request gitlab-org/gitlab-ce!24474

Fix compatability issue

Improve Review Apps documentation

See merge request gitlab-org/gitlab-ce!24597

[QA] Use public_email instead of email since it's available

Closes gitlab-org/quality/staging#27

See merge request gitlab-org/gitlab-ce!24533

Extract the EE specific codes in spec/factories/notes.rb

Closes #9079

See merge request gitlab-org/gitlab-ee!9269

Fix broken docs link

Closes #56754

See merge request gitlab-org/gitlab-ce!24611

Fix broken docs link

Closes gitlab-ce#56754

See merge request gitlab-org/gitlab-ee!9274

Clarify `ssh` and `https` cloning, as well as where to find the `url`s
to those repositories.

Signed-off-by: Rémy Coutable <remy@rymai.me>

Added `btn_class` to the dropdown for custom notifications

See merge request gitlab-org/gitlab-ce!24557

Externalize strings from `/app/views/sent_notifications`

See merge request gitlab-org/gitlab-ce!24576

Multiple environments support for feature flags (Unleash API standpoint)

See merge request gitlab-org/gitlab-ee!9110

Update Helm to 2.12.2 to address Helm client vulnerability

Closes #56417

See merge request gitlab-org/gitlab-ce!24418

Externalize strings from `/app/views/sent_notifications`

See merge request gitlab-org/gitlab-ee!9261

Signed-off-by: Rémy Coutable <remy@rymai.me>

Merge branch '56731-wait_for_job_to_be_done-gitlab-assets-compile-fails-in-the-review-build-cng-job' into 'master'

Resolve "`wait_for_job_to_be_done "gitlab:assets:compile"` fails in the `review-build-cng` job"

Closes #56731

See merge request gitlab-org/gitlab-ce!24598

Fix closing Markdown codeblock in Epics API docs

See merge request gitlab-org/gitlab-ee!9257

Resolve "Changing wording to "Delete" when referring to removing a branch"

Closes #25569

See merge request gitlab-org/gitlab-ce!23966

Add troubleshooting section to Slack Notification Service

See merge request gitlab-org/gitlab-ce!24339