Better UI feedback when user copies or saves.

[jerbaroo]

Thank you @jerbaroo but this request is opening a door that I don't really want to open. I think we need to add better UI feedback when user copies or saves.

Originally posted by @jtheoof in #176

[nuthub]

The original issue #176 is also somewhat related to #212. Maybe an implementation could allow for / to configure both:

1. Provide UI feedback (e.g. notification "image copied to clipboard") on Copying the binary image data AND/OR
2. Copy path/filename string of saved file + provide UI feedback (e.g. notification "filename copied to clipboard")

In my case it's also usually the case, that I take a screenshot and only after that, I decide whether I want to save the image to a file and [+ add the path to my clipboard (manager)] or to save the binary data to my clipboard (manager).