Linux multi-monitor setup support

[Avasam]

Is your feature request related to a problem? Please describe.

Currently AutoSplit on Linux only considers single-monitor setups.

Describe the solution you'd like

AutoSplit should be usable from any monitor targeting a window on any monitor.

Additional context

Extracted from #224

Linux in VMWare freaks out as soon as I try to have multiple monitors, the mouse and clicks locations are just way off. I'm not gonna attempts developing a solution in this state. Last I tried, WSLg wasn't too helpful here either.

[Avasam]

I'm now dual booting Linux, so I have a native multi-monitor setup.
Selecting a Window works fine. Selecting a region gives wildly incorrect coordinates.