Do not show full license ids without an explicit request

[novoselt]

When making a screenshot or having a video call or having a demonstration in class, one has to be mindful and careful not to post or open anything that shows full license ids. The full id is pretty much never needed to be displayed in the user interface - unless you are trying to copy-paste it somewhere.

So it would be better if only a few last characters were shown everywhere, and one had to click something to display the full key.

Maybe it should NEVER be displayed completely, but there is a button next to the partial key to put the full one into clipboard.

Free bonus: a few characters take less space to display than all the characters.