Update registry to include some of the commits for 2.7

Related to #3854 (closed)

Test plan:

• docker login
  • 2fa enabled
    • Login with user password should fail
    • Login with access token should work
    • Login with invalid password/token should fail
    • Login with expired token should fail
    • Login with revoked token should fail
  • 2fa disabled
    • Login with user password should work
    • Login with access token should work
    • Login with invalid password/token should fail
• docker push
  • pushing a valid image should work
  • pushing to a non-existant project should fail
  • private projects
    • should fail if user has not authenticated
    • should fail if user does not have permission
• docker pull
  • pulling a valid public image should succeed
  • pulling a non-existant image from a valid project should fail
  • pulling from a non-existant project should fail
  • private projects
    • should fail if user has not authenticated
    • should fail if user does not have permission
    • should succeed if user has permission, and has logged in
• GitLab UI registry page
  • Created images should be visible
  • Clicking the delete button should remove the image
• gitlab-ctl registry-garbage-collect works
• Valid backout plan