Overview

As suggested in #4623, Citra should support binding a hotkey to activate the frontend microphone implementation. Games that use the microphone tend to enable the mic while launching, even if the game is not going to read the data from the shared page till much later.

My personal design suggestions for implementors:

Support for this feature should fully stop any input streams on the host machine, meaning no data is getting read from any microphone or other sources, instead of simply skipping writes to guest. Only skipping writes could be surprising to users as Citra would be "using" their mic for their whole play session

Since Citra doesn't currently have any standard on toggle vs. hold hotkeys, this hotkey should be a hold hotkey, at least until we get a good way to let users choose toggle/hold. Push to talk is a very common practice in voice chat programs and games with builtin voice, so its a good enough default.

If anyone has other design suggestions for the hotkey, please leave them as comments so whoever works on this task can see other feedback about how to implement it.