Port of d11f8d24b0.
Followup to 187e10d8c9.
* removed `aria-label` in the diff template
* changed `Copy to clipboard` to `Copy path`
* left `copy_generic` for now, but it's unused
* ported the addition of this button to the file view template
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6079
Reviewed-by: Otto <otto@codeberg.org>
Co-authored-by: silverwind <me@silverwind.io>
