Remove duplicate ee code

This was generalized for usage in the new variable table design, see
https://gitlab.com/gitlab-org/gitlab-ce/issues/39118#note_53615249

Conflicts:
	app/assets/stylesheets/pages/projects.scss
	ee/app/assets/javascripts/protected_branches/protected_branch_create.js
	ee/app/assets/javascripts/protected_tags/protected_tag_create.js
	ee/app/views/projects/protected_branches/ee/_dropdown.html.haml