Geo: Improve replication status. Using pg_stat_wal_receiver

Closes #3256

See merge request gitlab-org/gitlab-ee!4187

Make Gitlab::Git::Repository#run_git private, EE version

See merge request gitlab-org/gitlab-ee!4228

Add Epic information for selected issue in Issue boards sidebar

Closes #4289

See merge request gitlab-org/gitlab-ee!4104

Update secret_values to support dynamic elements within parent -- EE merge edition

See merge request gitlab-org/gitlab-ee!4222

[EE]  Resolve "Re-enable the `RSpec/SingleLineHook` cop"

See merge request gitlab-org/gitlab-ee!4248

Move EE-specific migrations under ee/db/

Closes #3094

See merge request gitlab-org/gitlab-ee!3831

Geo project replication QA

See merge request gitlab-org/gitlab-ee!3893

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

Resolve "Asset was not declared to be precompiled in production, favicon-green.ico"

Closes #4666

See merge request gitlab-org/gitlab-ee!4212

Resolve "High rate of config.lock file errors on Geo testbed"

Closes #4693

See merge request gitlab-org/gitlab-ee!4249

CE upstream - Wednesday

Closes gitaly#921 and gitaly#929

See merge request gitlab-org/gitlab-ee!4242

Add modal for deleting a milestone (EE port)

Closes gitlab-ce#41314

See merge request gitlab-org/gitlab-ee!4157

This reverts commit 9f5390d8, reversing
changes made to c28ffa1d.

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

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

Adds correct illustration for pending state

See merge request gitlab-org/gitlab-ee!4209

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

 Conflicts:
   qa/qa.rb

(cherry picked from commit b8506500)

CI/CD end-to-end tests / EE

See merge request gitlab-org/gitlab-ee!4207

Conflicts:
  qa/qa.rb

Moves more mr widget components into vue files

See merge request gitlab-org/gitlab-ee!4235

Resolve "Spec failure in ./spec/features/issues/spam_issues_spec.rb"

Closes #42361

See merge request gitlab-org/gitlab-ce!16671

[ci skip]

[ci skip]

Used in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4110
which introduces a dynamic variable list and needs secrets.

We use the valueSelector/placeholderSelector options to avoid selecting
the last empty row.