Whenever we already deal with a User object, let's use the more specific
method avatar_icon_for_user.

See https://gitlab.com/gitlab-org/gitlab-ce/issues/42928

The refs hash is used to determine what branches and tags have a commit
as head in the network graph. The previous implementation depended on
Rugged#references. The problem with this implementation was that it
depended on rugged, but also that it iterated over all references and
thus loading more data than needed if for example the project uses CI/CD
environments, Pipelines, or Merge Requests.

Given only refs are checked the network cares about the GraphHelper#refs
method has no need to reject those, simplifying the method.

Closes gitlab-org/gitaly#880

Closes #40755.

Resolve "Add a link to documentation on how to get external ip in the Kubernetes cluster details page"

See https://gitlab.com/gitlab-org/gitlab-ce/issues/39118

Conflicts:
	app/views/ci/variables/_form.html.haml
	app/views/ci/variables/_table.html.haml
	ee/app/views/ci/variables/_environment_scope.html.haml
	spec/javascripts/ci_variable_list/ci_variable_list_ee_spec.js
	spec/javascripts/fixtures/projects.rb

From https://gitlab.com/gitlab-org/gitlab-ce/issues/36760

Was reverted in
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/14373

- Change button group width on mobile to 100%
- Added scrolling container to activity top area secondary navigation
- Added bottom border to top-area nav-links to separate them from nav-controls