Previously, we stored these as serialised fields - `st_{commits,diffs}` - on the
`merge_request_diffs` table. These now have their own tables -
`merge_request_diff_{commits,diffs}` - with a column for each attribute of the
serialised data.

Add a background migration to go through the existing MR diffs and migrate them
to the new format. Ignore any contents that cannot be displayed. Assuming that
we have 5 million rows to migrate, and each batch of 2,500 rows can be
completed in 5 minutes, this will take about 7 days to migrate everything.

Do not validate CSRF token in API unless needed

Closes #35705

See merge request !13256

Remove test gitaly when older than version file

See merge request !13250

Fly-out dropdown menu in new sidebar

Closes #34026

See merge request !12938

Fix Prometheus application settings help link to point to Prometheus help page

Closes #33921

See merge request !13258

Disable the Rails/Delegate cop

Closes #35869

See merge request !13267

Empty project factory by default

See merge request !13260

See https://gitlab.com/gitlab-org/gitlab-ce/issues/35869 for the
rationale.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Change project FK migration to skip existing FKs

Closes #35243

See merge request !13235

Add icons to project sidebar

Closes #34027 and #35877

See merge request !13204

Uniquify reserved word usernames on OAuth user creation

See merge request !13244

Synchronous zanata community contribution translation

Closes #35003

See merge request !13242

Show auto-generated avatars in Groups dashboard tree for Groups without avatars

See merge request !13188

Make Delete Merged Branches handle wildcard protected branches correctly

Closes #35592

See merge request !13251

Update milestone docs CE

See merge request !13233

The "Delete Merged Branches" button should filter out protected
branches matching the wildcard patterns.

Closes gitlab-org/gitlab-ce#35592.

This changes the migration ProjectForeignKeysWithCascadingDeletes so
that it does not add already existing foreign keys and indexes, making
it easier to re-run the migration.

Expose target_iid in Events API

See merge request !13247

Extending API for protected branches

See merge request !12756

Add rugged_is_ancestor method

See merge request !13232

Fix Issue board when using Ruby 2.4

Closes #35769

See merge request !13220

Make the 'issuables list meta-data' shared example less dangerous

See merge request !13236

Ensure all project factories use `:repository` trait or `:empty_project`

See merge request !13238

Add filtered search to group issue dashboard

Closes #33575

See merge request !13167