#153 Multiple monitor (desktop) support

[Hennadii]

When opening an application in full-screen mode, the following things are incorrectly detected:
1. current active monitor
2. screen size
Rendering occurs on the main one, but cannot on the additional (extended) one.

GetSystemMetrics is not quite the correct function to determine the current maximum size. What the documentation says.
https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getsystemmetrics
Since she gets the dimensions of the first one (bootload).