Merge Request > Changes tab. Add A file browser tree of all changed files, instead of one long scrolling page

Add a file browser to the "Changes" tab on the merge request screen. The file browser should contain a tree of all files that were changed in the commits that make up that merge request. A file browser allows the user to perform a code review on the changed files one file at a time

For larger pull requests sometimes it is hard to get people to effectively review a merge request especially because they have to keep scrolling to see every file that was changed.