Documentation + rubocop for checking that foreign key constraints require an index

Closes #49789

See merge request gitlab-org/gitlab-ce!20964

Allow the Web IDE to open empty merge requests

Closes #48166

See merge request gitlab-org/gitlab-ce!21102

Fix label item height when no desc

Closes #47928

See merge request gitlab-org/gitlab-ce!21106

Resolve "Job Failed #87997478"

Closes #50153

See merge request gitlab-org/gitlab-ce!21111

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

Phase 2: #47282 Improving Contributor On-Boarding Documentation

See merge request gitlab-org/gitlab-ce!20682

Resolve "docs update api for usage with an array of hashes"

Closes #49821

See merge request gitlab-org/gitlab-ce!20952

Backport of EE "catch entering username as an email instead of returning a 500 error"

See merge request gitlab-org/gitlab-ce!21085

Add Bitbucket Server importer docs

See merge request gitlab-org/gitlab-ce!21097

Update doc/integration/oauth_provider.md

See merge request gitlab-org/gitlab-ce!21093

Docs: fix ee-conflict in bulk editing

See merge request gitlab-org/gitlab-ce!21091

Closes #48166

Add details for https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20164.

Merge branch 'rd-fix-bug-when-authenticating-user-for-repo-with-size-check-enabled-ce' into 'master'

Backport of gitlab-org/gitlab-ee!6848

See merge request gitlab-org/gitlab-ce!21096

Closes #49789.

Fix Bitbucket Cloud importer omitting replies

Closes #50052

See merge request gitlab-org/gitlab-ce!21076

Remove redundant ci_builds (status) index

See merge request gitlab-org/gitlab-ce!21070

Enable more frozen string in app/models/**/*.rb

See merge request gitlab-org/gitlab-ce!21019

Keep project repository settings sections expanded after submitting form

See merge request gitlab-org/gitlab-ce!21082

Keep project settings sections expanded after submitting form

See merge request gitlab-org/gitlab-ce!21079

Keep group settings sections expanded after submitting form

See merge request gitlab-org/gitlab-ce!21083

CE port of "Add date fields to Epic to enable dates to source from milestones"

See merge request gitlab-org/gitlab-ce!20687

Update CONTRIBUTING.md

See merge request gitlab-org/gitlab-ce!21075

Update licenses and templates

See merge request gitlab-org/gitlab-ce!21084

Fix broken text in OAuth authorization screen

See merge request gitlab-org/gitlab-ce!21080