Fixes from CSS refactor

Closes #39001 and #38939

See merge request gitlab-org/gitlab-ce!14828

Resolve "Prometheus service page shows error"

Closes #35652

See merge request gitlab-org/gitlab-ce!14771

Shorten example translation for inclusive language

See merge request gitlab-org/gitlab-ce!14833

Add docs for GKE integration

See merge request gitlab-org/gitlab-ce!14712

Fix a missing link and create a separate "Testing guides" section

See merge request gitlab-org/gitlab-ce!14819

Merge branch '39033-d3-js-is-being-included-in-the-user_profile-and-graphs_show-bundles' into 'master'

Resolve "d3.js is being included in the user_profile and graphs_show bundles"

Closes #39033

See merge request gitlab-org/gitlab-ce!14826

Add project fields to import project by url

Closes #39028

See merge request gitlab-org/gitlab-ce!14822

Remove unnecessary alt-texts from pipeline emails

See merge request gitlab-org/gitlab-ce!14602

Cleanup data-page attribute after each Karma test

Closes #38871

See merge request gitlab-org/gitlab-ce!14742

Replace the 'features/explore/projects.feature' spinach test with an rspec analog

See merge request gitlab-org/gitlab-ce!14755

37660 Change background color of nav sidebar to match other gl sidebars

Closes #37660

See merge request gitlab-org/gitlab-ce!14800

Moves form related JS modules out of global

See merge request gitlab-org/gitlab-ce!14780

Backport EE change for setting up forked project

See merge request gitlab-org/gitlab-ce!14817

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/38871

Pass git object dir attributes as relative paths to Gitaly

Closes gitaly#629

See merge request gitlab-org/gitlab-ce!14713

Add inclusive language to translation guidelines

See merge request gitlab-org/gitlab-ce!14815

Update image commenting MR link in docs

See merge request gitlab-org/gitlab-ce!14816

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

Fixes gitaly#629

Fix a feature spec failing only on MySQL

Closes #39003

See merge request gitlab-org/gitlab-ce!14811

Add support for markdown preview to group milestones

Closes #30241

See merge request gitlab-org/gitlab-ce!14806

fix the import :milestone from adding the group_id

Closes #35580

See merge request gitlab-org/gitlab-ce!14657

Use Gitaly's RepositoryService.HasLocalBranches RPC

See merge request gitlab-org/gitlab-ce!14753

Add sort runners on admin runners

Closes #38720

See merge request gitlab-org/gitlab-ce!14661

Move callback route(`google_api/auth/callback`) for Oauth under `-`

Closes #38911

See merge request gitlab-org/gitlab-ce!14802

Simplify project page

Closes #37399 and #38839

See merge request gitlab-org/gitlab-ce!14669

Developer can create/edit/delete milestones

See merge request gitlab-org/gitlab-ce!14797