Draft: Add Toggle all files functionality

What does this MR do and why?

This MR adds Toggle all files functionality when toggling a single file with Alt key pressed.

Context: Collapsing file in diffs tab causes unexpected ... (#360204 - closed) (internal).

Screenshots or screen recordings

Screen_Recording_2023-11-24_at_16.05.10

Toggle file title

Screen_Recording_2023-11-28_at_13.22.39

How to set up and validate locally

1. Open any MR which contains at least 2 files changed
2. Click on Toggle file button with Alt key pressed
3. All files should be collapsed
4. Repeat step 2
5. All files should be expanded