Set default cache key to 'default' for jobs

Closes #22419

See merge request !9666

Bring back api/builds.md and direct to api/jobs.md

See merge request !9761

[ci skip]

Make a default namespace of Kubernetes service to contain project ID

Closes #28516

See merge request !9741

Backport protected branches Ruby change from EE

See merge request !9726

Nested groups path restrictions pt. 1

See merge request !9738

Add git version to gitlab:env:info

Closes #25376

See merge request !9128

Performance improvement on Projects::BuildsController#show.html

Closes #28019

See merge request !9149

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/9666#note_24877665

* upstream/master: (289 commits)
  re-add Assign to Me link on new MR/Issue forms
  thinner bottom header border
  make header match old 16px padding of body contents
  Update font-awesome-rails to 4.7.0.1
  Relax font-awesome-rails dependency to ~> 4.7
  Restore keyboard shortcuts for "Activity" and "Charts"
  fix border radius bottom for header
  match padding for mr-widget sections
  Update changelog
  Fix project-last-commit alignment
  Docs: update GL Pages IP on GL.com
  Fix up @DouweM review
  Remove readme-only project view preference
  Add `uploads` to known models for Import/Export spec
  Add `has_many` associations for models that can have Upload records
  Handle relative and absolute Upload paths in the Uploaders
  Change the default CarrierWave root path for tests
  Fix Projects::UploadService spec
  Add a Project::UploadsController spec to ensure an Upload is created
  Add `RecordsUploads` module to record Upload records via callbacks
  ...

Fix project-last-commit alignment

See merge request !9745

Remove readme-only project view preference

See merge request !9744

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

re-add Assign to Me link on new MR/Issue forms

Closes #23948

See merge request !9499

Merge request widget merged state styling

See merge request !9352

Resolve "Relax `font-awesome-rails` dependency"

Closes #19062

See merge request !9748

Add emoji images - Base Native Unicode Emojis

Closes #26371

See merge request !9569

Backport change introduced in EE - alias for empty states SVGs

See merge request !9683

Simplify project payload exposed on Environment endpoints in V4

Closes #28598

See merge request !9675

Use publish channel to post notifications changes

See merge request !9574

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

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

Restore keyboard shortcuts for "Activity" and "Charts"

Closes #28538

See merge request !9680

Native Unicode Emojis

See merge request !9570

Record file uploads in the database

See merge request !8893

Remove tooltips and titles from label subscription buttons

See merge request !9692