Feature: Allow "Show in separate window" for diff viewers in more places

[sken130]

Currently, the "Show in separate window" button is available in "History --> Show details on a commit" only.

I would like it to be extended to:

• Local Changes --> Click on individual files --> the diff panel itself to be shown in separate window
• Stashes --> Click on individual files --> allow the diff panel itself to be shown in separate window

And such separate window should better display the file path (relative to repo) somewhere.

Also please provide shortcut key for opening separate window and closing it, thanks.