Make ActiveRecordSubscriber rails 5 compatible

Closes #44702

See merge request gitlab-org/gitlab-ce!19276

Add merge requests list endpoint for groups

Closes #45082

See merge request gitlab-org/gitlab-ce!18915

Fixes redudant script failure message

Closes #46552 and #44271

See merge request gitlab-org/gitlab-ce!19138

Take two for MR metrics population background migration

See merge request gitlab-org/gitlab-ce!19097

Add yarn clean step, to delete production compiled assets

See merge request gitlab-org/gitlab-ce!19212

Fix active tab styling

Closes #46799

See merge request gitlab-org/gitlab-ce!19264

Add link to hack for styling Capybara HTML dumps

See merge request gitlab-org/gitlab-ce!19205

Export assigned issues in iCalendar feed

Closes #44184

See merge request gitlab-org/gitlab-ce!17783

Eliminate cached N+1 queries for projects in Issue API

See merge request gitlab-org/gitlab-ce!19269

Use strings as properties key in kubernetes service spec.

See merge request gitlab-org/gitlab-ce!19265

Add /vendor/gitaly-ruby to gitignore

See merge request gitlab-org/gitlab-ce!19261

Replace .having with .where in calendar query

Closes #46964

See merge request gitlab-org/gitlab-ce!19230

Replace `.exists` with `EXISTS ()`

Closes #46277

See merge request gitlab-org/gitlab-ce!19178

Use Gitaly 0.104.0

See merge request gitlab-org/gitlab-ce!19258

Fix encoding bug in Gitaly::Commit::TreeEntry

Closes #46445 and gitaly#1208

See merge request gitlab-org/gitlab-ce!19243

Merge branch '45520-remove-links-from-web-ide-unexpectedly-navigate-you-to-a-different-page' into 'master'

Resolve "Remove links from Web IDE unexpectedly navigate you to a different page"

Closes #45520

See merge request gitlab-org/gitlab-ce!19129

Cleanup code for General Project Settings

See merge request gitlab-org/gitlab-ce!19245

Adjust permitted params filtering on merge scheduling

Closes #46903

See merge request gitlab-org/gitlab-ce!19255

Resolve "Unable to start rails console if using master from gitlab-shell"

Closes #46991

See merge request gitlab-org/gitlab-ce!19251

Fix cattr_accessor definition

Closes #46282

See merge request gitlab-org/gitlab-ce!19192

Removal of API v3 from the codebase

Closes #36819

See merge request gitlab-org/gitlab-ce!18970

Resolve "Extra whitespace when hovering commit sha in MR widget"

Closes #46971

See merge request gitlab-org/gitlab-ce!19267

Fix various bugs related to relative_url_root in development

See merge request gitlab-org/gitlab-ce!19213

In CE, every `Issue` entity is also a `ProjectEntity`, which calls
`entity&.project.try(:id)` to show the project ID. In an API
request with 100 issues, this would hit the Rails statement cache 100 times
for the same project and cause unnecessary overhead as related models would
also be loaded.

In EE, we call `Issue#supports_weight?` for each issue, which then calls
`project&.feature_available?(:issue_weights)`. If the project is not
preloaded, this incurs additional overhead, as each individual Project
object has to be queried. This can lead to a significant performance hit.
In loading the CE project with 100 issues, this contributed to at least 22%
of the load time.

See https://gitlab.com/gitlab-org/gitlab-ce/issues/47031 for why testing this
is a bit tricky.

Improve structure of snippets documentation

See merge request gitlab-org/gitlab-ce!19234

Add Wiki and Snippets to project feature overview

See merge request gitlab-org/gitlab-ce!19235

* master: (32 commits)
  Update CHANGELOG.md for 10.8.3
  Update "col-xs" usage to bootstrap4
  Add missing usage_ping_enabled to API settings
  Make Repository#blob_data_at a public method
  Fix UI broken in line profiling modal due to Bootstrap 4
  Only preload member records for the relevant projects/groups/user in projects API
  Fix   after sign-in with Google button
  Fix a wrong link reference in docs
  Simplify spec: `2.times.each` -> `2.times`
  Replace grape-route-helpers with our own grape-path-helpers
  Add archived param to the json response
  Consider we might have prefix for stable branches
  Convert spec/javascripts/.eslintrc to yml format as well
  Remove version lock on awesome_print dependency
  Fix import project by url layout
  Fix missing timeout value in object storage pre-authorization call
  fix last lints
  disable no-multi-assign
  fix `spaced-comment`
  remove unused createComponentWithMixin from vue spec helpers
  ...

[ci skip]

Update "col-xs" usage to bootstrap4

Closes #47002

See merge request gitlab-org/gitlab-ce!19256