Load balancing of database queries

See merge request !1283

Strip out `nil`s in the Array of Commit objects returned from `find_commits_by_message_with_elastic`

Closes #835

See merge request !1430

Port of issue boards filter bar in modal window to EE

See merge request !1435

Expose GitLab QA failure screenshots for EE hooks

See merge request !1440

Strip out `nil`s in the Array of Commit objects returned from `find_commits_by_message_with_elastic`

This commit also removes an N-query issue with the Project lookups on the class-level version of this method

Port of 27376-cache-default-branch-pipeline-on-project to EE

See merge request !1441

Add docs to CSV export

See merge request !1389

20450 fix ujs actions ee

See merge request !1370

Better priority sorting

See merge request !1429

Adds ExportCsvWorker spec

See merge request !1433

Moved the gear settings dropdown in the group view to a tab

See merge request !1409

prevent filtering Issues by multiple milestones, authors, or assignees

See merge request !1410

Remove pushes count from usage ping payload

Closes #1858

See merge request !1432

This query is constantly generating timeout errors on large installations and we don't
have a simple solution for now and also we don't think having this counter is
really critical.

For all timetracking props, include annotations

Closes #1428

See merge request !1405

Add a note about ES update to the GitLab update guide

Closes #1585

See merge request !1428

to the first option inside said subtab.

Also code cleanup

This reverts merge request !1426

Port of 27376-cache-default-branch-pipeline-on-project to EE

See merge request !1426

Fix rake gitlab:env:info elasticsearch datum

Closes #1164

See merge request !1422

Port of issue-boards-new-search-bar to EE

See merge request !1397