[OPTIMIZATION] Battery optimization with closing chat like CONTROL+SHIFT+C dose it

[CatWithCode]

Signal desktop needs far less battery if you close chats (CONTROL+SHIFT+C).

The responsive design mod is nice but dose not close the chat in the background.
If I press CONTROL+SHIFT+C the design reacts to it and dose the leaving chat animation meaning the responsive.js should not need to much changing.

The change needed here would be to check what code is executed in signal if someone presses CONTROL+SHIFT+C and add it to addBackButtonToChatView action.

[pparent76]

Thank's for pointing this out I will make some tests around that.

Feel free to make a pull request as well if you have the solution.