Use safe navigation operator to make rubocop happy

See merge request !9185

Feature to create directly addressed Todos when mentioned in beginning

Closes #24976

See merge request !7926

Updated issue boards docs

Closes #27872

See merge request !9097

Add member: Always return 409 when a member exists

Closes #20732

See merge request !9093

removes grayish blue color for events activity

Closes #27608

See merge request !9179

Gather issuable  metadata to avoid n+ queries on index view

Closes #25900

See merge request !9006

Update Rubocop to Ruby 2.3

See merge request !8994

Move merge requests index file inside the merge_requests dir

See merge request !9181

[ci skip]

Fix issue from milestone

See merge request !8895

Add method for creating foreign keys concurrently

See merge request !9069

Rename Files::DeleteService to Files::DestroyService

See merge request !9110

Resolve "Improve blockquote formatting in notification emails"

Closes #28029

See merge request !9157

Convert some vendored javascript assets to npm modules

See merge request !8990

fixes MR widget jump

Closes #27994

See merge request !9146

* master: (26 commits)
  Revert "Merge branch 'add-additional-checks-to-ca-data' into 'master'"
  Fix broken test to use trigger in order to not take tooltip overlaping in consideration
  Fix job to pipeline renaming
  Added env external link and light web terminal spec
  Don't perform Devise trackable updates on blocked User records
  Replace teaspoon references with Karma
  Add changelog
  Only show MR widget graph if there are stages
  Remove orange caret icon from mr widget
  Add index to ci_trigger_requests for commit_id
  rspec_profiling: Discover the correct branch name in GitLab CI
  Show parent group members for nested group
  Fix tooltip scss for anchors. Adds css for button's tooltips to have similar behavior. Removes padding from mini graph table cell to guarantee stages don't break line on hover
  Updated protected branches dropdown image in docs
  Fix admin_labels_spec.rb transient failure
  Make sure events have most properties defined
  Restore exposure of legend property for events
  moved hyperlink reference section at the end of the content
  Make sure our current .gitlab-ci.yml is valid
  adds changelog
  ...

Remove fixed positioning from navbar

See merge request !7547