Add support for getting and setting window data

[Foxbud]

This includes adding the ability to:

• Query whether the game window is in fullscreen or windowed mode.
• Change the game window from fullscreen to windowed mode and back.
• Query the size (in pixels) of the game window.
• Change the size (in pixels) of the game window.
• Get the position of the window's view into the game room.
• Translate positions between window and room space.