Avoid calculation of closes_issues.

## What does this MR do?

Avoid unneeded calls to MR closes issues

## Are there points in the code the reviewer needs to double check?

I'm not sure if calling this method from a view is a good practice, but I cannot see another simple way of avoiding this problem. In case we want to avoid this in the controller we need to specify the action, format and status of the merge request, because in that case we know that the `_open` partial will render. We could add some lazy evaluation but it not a thing I see in use along the app but feedback is welcome

## What are the relevant issue numbers?

#14202 , #19490

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- ~~[ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~
- ~~[ ] API support added~~
- Tests
  - ~~[ ] Added for this feature/bug~~
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5140

Allow specifying protected branches using wildcards

Closes #18627 

# Tasks

- [ ]  #18627 !4665 Allow specifying protected branches using wildcards
    - [x]  Find existing usages of protected branches
        - Protecting branches
            - `ProtectedBranchesController` is used to mark a branch protected/unprotected
            - `API::Branches` can be used to mark a branch protected/unprotected
        - Enforcing branch protection
            - `Gitlab::GitAccess` has helpers (`can_push_to_branch?`, `check`) that are used to deny pushes if a branch is protected
            - Over SSH: `gitlab-shell` receives a push, and calls `/allowed` on the GitLab API, which calls `GitAccess.check`
            - Over HTTP: 
                - `gitlab-workhorse` receives the request, and forwards it to rails
                - Rails (in the `GitHttpController#git-recieve-pack`) runs basic checks (is the user logged in, not protected branch checks) and returns ok with `GL_ID` and `RepoPath`
                - `gitlab-workhorse` looks at the response, and calls the relevant `gitlab-shell` action from `git-http/handlePostRPC`
                - Rest of this flow is the same as the SSH flow above
    - [x]  Implementation
        - [x]  Backend
            - [x]  Change `project#protected_branch?` to look at wildcard protected branches
            - [x]  Change `project#developers_can_push_to_protected_branch?`
            - [x]  Change `project#open_branches`
            - [x]  Better error message when creating a disallowed branch from the Web UI
        - [x]  Frontend
            - [x]  Protected branches page should allow typing out a wildcard pattern
            - [x]  Add help text explaining the use of wildcards
            - [x]  Show matching branches for each protected branch
                - [x]  ~~On the index page~~
                - [x]  On a show page
                - [x]  Index?
            - [x]  Can't have the "last commit" column for wildcard protected branches
    - [x]  Fix / write tests
    - [x]  What happens if a hook is missing in dev?
    - [x]  Refactor
    - [x]  Test workflows
        - Create a branch matching a wildcard pattern
        - Push to a branch matching a wildcard pattern
        - Force push to a branch matching a wildcard pattern
        - Delete a branch matching a wildcard pattern
        - [x]  Test using Web UI
        - [x]  Test over SSH
        - [x]  Test over HTTP
        - [x]  Test as developer and master
    - [x]  Investigate performance
        - [x]  Test with a large number of protected branches / branches
        - [x]  Paginate list of protected branches
        - [x]  ~~Possibly rewrite `open_branches`~~
    - [x]  Add `iid`s to existing `ProtectedBranch`es
    - [x]  Add documentation
    - [x]  Add CHANGELOG entry
    - [x]  Add screenshots
    - [x]  Make sure [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/2f753e3ed2ce681b4444944d521f4419e8ed37f7/builds) passes
    - [x]  Assign to endboss for review
    - [x]  Address @DouweM's comments
        - [x]  `protected_branch_params`
        - [x]  `exact_match` instead of `explicit_match`
        - [x]  When would self.name be blank?
        - [x]  Move `protected_branches.each` to a partial
        - [x]  Move `matching_branches.each` to a partial
        - [x]  If the branch is in @matching_branches, it's not been removed
        - [x]  move this regex to a method and memoize it
        - [x]  `commit_sha` directly for exact matches
        - [x]  Number of matches for wildcard matches, with a link
    - [x]  Wait for [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/43f9ce0e88194b8f719bb1c1e656b7fc13278d56/builds) to pass
    - [x]  Respond to @DouweM's comments
        - [x]  Don't use iid
        - [x]  Controller should use `@project.protected_branches.new`
        - [x]  move the memoization to `def wildcard_regex`
        - [x]  render with `collection: @protected_branches`
    - [x]  Wait for [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/f7beedf122fa0c7aa89e86181fe7499321fb10ca/builds) to pass
    - [x]  Wait for @DouweM's review
    - [x]  Wait for @jschatz1's review
    - [x]  Respond to @jschatz1's comments
        - [x]  Use the new dropdown style
        - [x]  description should be moved to the description section without the styling
        - [x]  Protect button should be disabled when no branch is selected
    - [x]  Update screenshots
    - [x]  Merge conflicts
    - [x]  Make sure [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/20f3cfe8d5540eab64c2ba548043d600b28c61ba/builds) passes
    - [ ]  Revisit performance, possibly with staging/production data
        - [ ]  Get a dump of staging / run against staging live
            - [ ]  Get SSH access to staging
    - [ ]  Wait for review/merge






# Screenshots

## Creating wildcard protected branches

![1](/uploads/9446afccfdf6fa381e00c800dd2cc82e/1.png)
![2](/uploads/0b154503b297a818d3577488c575d845/2.png)
![3](/uploads/36217f79df9e41cc1550601f02627fe8/3.png)
![4](/uploads/041ca9bd529bcfa5373fca67e917cbcb/4.png)

### Using the `GLDropdown` component

![2016-06-30_14-16-15](/uploads/508afc2a5e2463c2954641409a560d88/2016-06-30_14-16-15.gif)

## Enforcing wildcard protected branches

### From the Web UI

![Screen_Shot_2016-06-20_at_1.21.18_PM](/uploads/8b5d4b1911e9152698a0488daf1880bc/Screen_Shot_2016-06-20_at_1.21.18_PM.png)

### Over SSH

![SSH](/uploads/7365989d7e4c406ef37b6ae5106442c9/SSH.gif)

### Over HTTPS

![HTTPS](/uploads/a7c0f56ae58efcffc75e6700fa2f4ac0/HTTPS.gif)

## Listing matching branches

![Screen_Shot_2016-06-20_at_1.33.44_PM](/uploads/d054113022f5d7ec64c0e57e501ac104/Screen_Shot_2016-06-20_at_1.33.44_PM.png)

See merge request !4665

We just need to get merge requests closes issues when 
we’re going to show them

1. Modify the component to support a callback for every key press in the
   filter. We need this so we can update the "Create: <branch_name"
   label.

2. Modify the component to use `$(<selector>).first().click()` instead
   of `$(selector)[0].click()`, because the latter is non-standard, and
   doesn't work in PhantomJS.