Add shortcuts to switch between two modes

[mvicomoya]

First of all, I just want to thank you @wheaney for the great work you are doing around supporting XR glasses on Linux with Breezy Desktop and this Steam Deck plugin.

So the feature I'm actually after is to have some shortcut to be able to move the virtual screen to a corner quickly and disable the electromagnetic film on my Viture XR Pro glasses.

With the current implementation of the plugin it may not be too complicated to allow users to define "main" and "secondary" modes that you can swap quickly. I could for instance have follow mode with the screen on a corner as secondary mode and accomplish the PIP mechanism that I'm after.

I think the challenging part would be to hook this logic up to a press of a button on the glasses, or a combination of buttons on the Deck. As far as I can tell, there's currently no way for Decky plugins to get input events while running in the background, but I might be wrong. Also, not sure if the current Viture Linux SDK allows for getting button events either.

Anyway, I just wanted to throw this idea here to see if you @wheaney have any insight.

Not having much time for personal projects lately, but I wouldn't mind trying to put together a PR myself for this if it's technically possible. I don't think it's desirable to build upon the multi-tap mechanism that you came up with, but maybe that's the only option.

[wheaney]

Most of my plugin's functionality comes from the driver that runs as a systemd service, so it could definitely watch for key/button events.

The VITURE SDK doesn't give me access turn turn on/off the tint, but I think it's possible. I'll have to ask them if they can add it.