Render MR page when no persisted diff_refs or diffs size

Closes #49342

See merge request gitlab-org/gitlab-ce!20680

Update index.md to add link to reducing repo size doc

See merge request gitlab-org/gitlab-ce!20281

Backports security reusable components into CE to use in JUnit report

See merge request gitlab-org/gitlab-ce!20613

Resolve "broken breadcrumb in admin/user when switching tabs"

Closes #47419

See merge request gitlab-org/gitlab-ce!19608

Features/show project id on home panel

Closes #46342

See merge request gitlab-org/gitlab-ce!20305

Merge dev master to CE .com master as part of the security release process

Closes #49133

See merge request gitlab-org/gitlab-ce!20681

Fix symlink vulnerability in project import

See merge request gitlab/gitlabhq!2440

Resolve "Redesign GCP banner"

Closes #48804

See merge request gitlab-org/gitlab-ce!20542

Merge branch '49257-metrics-drop-down-doesn-t-show-all-environment-some-not-clickable' into 'master'

Resolve "Metrics drop down doesn't show all environment, some not clickable"

Closes #49257

See merge request gitlab-org/gitlab-ce!20651

Fix ide-tree-header button background

See merge request gitlab-org/gitlab-ce!20662

  * Fix broken breadcrumb when switching tabs in admin/user

Closes #47419

Extract EE-specific lines from Banzai pipelines

See merge request gitlab-org/gitlab-ce!20636

Enable frozen string in app/services/**/*.rb

See merge request gitlab-org/gitlab-ce!20656

Update specific runners help URL

See merge request gitlab-org/gitlab-ce!20213

Include full image URL in webhooks for uploaded images

Closes #20720

See merge request gitlab-org/gitlab-ce!18109

Resolve "MR: Reduce the memory footprint of the component tree"

Closes #48964

See merge request gitlab-org/gitlab-ce!20448

Add merge request header branch actions left margin

Closes #49238

See merge request gitlab-org/gitlab-ce!20643

Resolve "Pipeline graph in new merge request widget is flickering"

Closes #49165

See merge request gitlab-org/gitlab-ce!20660