Provide some feedback after copying commit hash

[MarcelBochtler]

Is your feature request related to a problem? Please describe.
I use the Copy Hash [y] feature in the log view quite often. Unfortunately, this feature offers no visual feedback when the key was hit.

Describe the solution you'd like
It would be great to get some visual feedback when the hash was copied.
E.g. show a small overlay / popup, that the hash was successfully copied.

[stale]

This issue has been automatically marked as stale because it has not had any activity half a year. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[extrawurst]

Should be easy to implement as we have arbitrary message popup for this already