Support windowed fullscreen

We should allow usage of the SDL_WINDOW_FULLSCREEN_DESKTOP flag instead of SDL_WINDOW_FULLSCREEN. This allows borderless window fullscreen over exclusive fullscreen.

Difference is described here https://wiki.libsdl.org/SDL_SetWindowFullscreen

To not mess with existing settings I propose we add another setting on top of fullscreen.

fullscreen = true
borderless fullscreen = true

In our settings managers, we can change the fullscreen checkbox (both in-game and launcher) to a dropdown with three options:

1. Fullscreen
2. Borderless Fullscreen
3. Windowed