Searching for a branch on Create Branch or on Setting the Main branch does not pull best/exact matches first

Issue Summary

When searching for a branch, Bitbucket only displays 25 results which means if the result you are looking for is after the 25th result even after using filters, you won't be able to pick it.

The list that is provided comes in the same order as git branch command and does not provide exact matches or close matches first.

@croos The main branch dropdown has the same bug, it only displays 10 results. Even after using filters, you won't be able to pick it. 

Steps to Reproduce

1. Creating a branch
   1. In a repository with 26 branches or more, open the branches page
   2. Click on Create Branch
   3. On the From branch dropdown, specify the branch that you want as parent. Note only 25 branches are displayed. This is not possible to create a branch from a parent if that is parent branch is not in the list of 25 branches
2. Setting the Main branch
   1. Go to Repository settings in a repository with 11 branches or more
   2. Expand ADVANCED button on the right side
   3. Click on Main branch dropdown to select the Main branch
   4. Specify branch to be setup as main branch, note 10 branches are displayed. This is not possible to setup the main branch if that is not listed in the list of 10 branches

Expected Results

If a filter matches the exact branch, the branch would be displayed.

Actual Results

Searching for a branch using a pattern, if its not listed in the top 25 (or 10 for settings a main branch) results, the branch won't be displayed.

Workaround

While searching for the branch in a Create branch page
  As a workaround, it is possible to create a branch based on another branch locally and then push the new branch to Bitbucket.
While searching for the branch in setting the main branch
  As a workaround, the customer can type to search for that specific branch, this is a hidden feature that the customer may or may not know. You should be able to get the list of all branches matching the pattern.