Gitaly n+1 times per request on Project Branches (performance)

Background:

As Projects::BranchesController#show is slow, its performance should be improved.

• e.g.) https://tools.pingdom.com/#!/cITcVf/https://gitlab.com/gitlab-org/gitlab-ce/branches/all
  • X-Runtime: 5.542384

Links / references:

• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15402#note_50059470