[client] Keyboard shortcut for minimize window

[Salamafet]

It would be great to have a keyboard shortcut to minimize the window even if looking-glass is in full-screen mode.
This shortcut exists on Moonlight and is very convenient to return rapidly to the host machine without close the client.

In my case, I use my VM only for gaming. Discord and other communication software is running on my host machine.

Thanks for your very great work 👍

[MadelineRitchie]

I understand the desire for this, but LG opens and closes so fast I wonder what the difference is between hitting scrolllock-q and minimizing it

[UnaTried]

Isn't this kind of a duplicate of #917?