do window bound checks without relying on displayId

Fixes Vesktop not remembering its position correctly.
Seems like the display ids aren't consistent on some windows systems...

src/shared/settings.d.ts

@@ -51,7 +51,6 @@ export interface State {
     maximized?: boolean;
     minimized?: boolean;
     windowBounds?: Rectangle;
-    displayId: number;
 
     firstLaunch?: boolean;