Summary:
When looking at a commit/revision, allow to copy the path of a file to the clipboard, so you can quickly open that file in your local code checkout from the command line.
Closes T15897
Test Plan:
Open a proposed commit in Differential or a merged commit in Diffusion. Click the "Copy file path" button, paste that clipboard content.
Change the width of the viewport and see that the button is not rendered when in phone mode.
Run `./bin/celerity map` again and no changes.
Reviewers: O1 Blessed Committers, valerio.bozzolan
Reviewed By: O1 Blessed Committers, valerio.bozzolan
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T15897
Differential Revision: https://we.phorge.it/D25757
ec6ba69666