Convert issue board switcher to gitlab-ui dropdown components

Closes #9088 and #8855

See merge request gitlab-org/gitlab-ee!8591

[Part 1] Add Epic sidebar shell to refactored Epics app

See merge request gitlab-org/gitlab-ee!9289

Upgrade webpack and monaco-editor to latest

See merge request gitlab-org/gitlab-ce!24646

Improve Target audience section for issue templates

See merge request gitlab-org/gitlab-ce!24527

Add missing attrs to Issue example API responses

See merge request gitlab-org/gitlab-ce!24641

Add upvote/downvote counts to Epics API

Closes gitlab-ce#56723 and #6769

See merge request gitlab-org/gitlab-ee!9264

Docs: fix typos on API page

See merge request gitlab-org/gitlab-ce!24657

Specify use of custom helm chart per env

See merge request gitlab-org/gitlab-ce!24541

Resolve "Commit comments displayed on a merge request that contains that commit no longer specify which commit they come from"

Closes #53950

See merge request gitlab-org/gitlab-ce!24427

EE Port of Display "commented" only for commit discussions

See merge request gitlab-org/gitlab-ee!9232

Unified commit link in note header action text

Unified commit link in note header action text

Geo - Turn Gitlab::Geo::Fdw into a class

Closes #6097

See merge request gitlab-org/gitlab-ee!9263

Provide more information of release cadence

See merge request gitlab-org/gitlab-ce!24479

Provide more information of release cadence

See merge request gitlab-org/gitlab-ee!9221

Includes upvotes/downvotes counts on the epics API endpoints

remove red/green colors from diff view of no-color syntax theme

See merge request gitlab-org/gitlab-ce!24582

Split project menu into separate submenus

See merge request gitlab-org/gitlab-ce!24501

Resolve "Runners IPv6 address overlaps other values"

Closes #56334

See merge request gitlab-org/gitlab-ce!24531

Document broadcast messages in UI

Closes #45801

See merge request gitlab-org/gitlab-ce!24556

Document broadcast messages in UI

See merge request gitlab-org/gitlab-ee!9248