This adds toggle buttons to switch between file & tree list.
For file list, it renders the truncated paths with the ellipsis
at the start of the path.
When focusing the input, it hides the toggle buttons.
On blur, the buttons get shown again.
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51859
This file tree displays all the diff files in a tree like format
Each file is taken and converted into a tree with folders
Each folder can be toggled open & closed
Clicking a file will scroll to the diff file & highlight with a glow affect
Searching the tree list will search only files & return a list of the
files without any folders
Each file row contains an icon to show changed, new file or deleted
Each row will also contain the added & removed lines count
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/14249
Phil Hughes