Implement customized sidebar

Closes #14995

See merge request gitlab-org/gitlab-ce!17940

Migrate merge base, merged branches, write ref

Closes gitaly#748, gitaly#695, and gitaly#799

See merge request gitlab-org/gitlab-ce!20639

Add emails delivery metrics

Closes #49214

See merge request gitlab-org/gitlab-ce!20638

Resolve "Change API docs to reflect that lookup by username does not require admin access"

Closes #38095

See merge request gitlab-org/gitlab-ce!20646

Update pipelines.md to have correct curl commands

See merge request gitlab-org/gitlab-ce!20653

Fix archived parameter for projects API

Closes #32301

See merge request gitlab-org/gitlab-ce!20566

Fix typo in CSS transform property for Memory Graph component

Closes #49291

See merge request gitlab-org/gitlab-ce!20650

Resolve "NoMethodError: undefined method `namespace' for nil:NilClass"

Closes #49061

See merge request gitlab-org/gitlab-ce!20615

Enable frozen string in apps/services/*.rb

See merge request gitlab-org/gitlab-ce!20401

* upstream/master: (53 commits)
  Fix invalid link to GitLab.com architecture.md
  i18n: externalize strings from 'app/views/import'
  Remove Repository#lookup and unreachable rugged code
  refactor code based on feedback
  Trigger rails5 tests either by variable or ref name
  Fix link in help doc which was linking to old mono-repo, now in its own repo
  Allow Danger step to fail
  update webpack to v4.16
  Backport logger changes from EE
  Add the CI Job trigger as the build trigger
  Remove flaky and redundant expectations
  use fileuploader dynamic path method in uploads manager and add spec
  fix typo in uploads manager
  add small comment to download method in uploads manager
  refactor uploads manager
  Update 10.6-to-10.7.md
  Lazy-load performance bar UI
  Update .gitlab-ci.yml
  fixed test to correctly text relative URLs doesnt add query param if source & target projects match
  Add changelog entry
  ...

Update issue closing pattern

Closes #49166

See merge request gitlab-org/gitlab-ce!20554

Update Git version to 2.18.0

See merge request gitlab-org/gitlab-ce!20489

Fix invalid link to GitLab.com architecture.md

See merge request gitlab-org/gitlab-ce!20645

Add a 10 ms bucket for SQL timings

See merge request gitlab-org/gitlab-ce!20527

i18n: externalize strings from 'app/views/import'

See merge request gitlab-org/gitlab-ce!19732

Partially addresses #47424.

Move "search by email or username" block to "for normal users" section

Signed-off-by: Tao Wang <twang2218@gmail.com>

Update 10.6-to-10.7.md

See merge request gitlab-org/gitlab-ce!20610

Remove Repository#lookup and unreachable rugged code

See merge request gitlab-org/gitlab-ce!20553

Merge branch '48745-project-exports-fail-when-uploads-have-been-migrated-to-object-storage' into 'master'

Resolve "Project exports fail when uploads have been migrated to object storage"

Closes #48745

See merge request gitlab-org/gitlab-ce!20484

Make it more explicit what environment stop actions are

Closes #48672

See merge request gitlab-org/gitlab-ce!20587

i18n: externalize strings from 'app/views/doorkeeper'

See merge request gitlab-org/gitlab-ce!19695

Add the CI Job trigger as the build trigger

Closes charts/gitlab#586

See merge request gitlab-org/gitlab-ce!20619

QA: Remove flaky and redundant expectations

Closes #49164

See merge request gitlab-org/gitlab-ce!20616

Trigger rails5 tests if variable is set

See merge request gitlab-org/gitlab-ce!20609