Add fullscreen options to GlfwContext

• Add fullscreen functionality to GlfwContext
  • Save window position and size on entering fullscreen to restore the window properly
• Remove fullscreen code from GlfwApp
• Add fullscreen support to window size/position disk-caching in GlfwApp
• Rename internal_sceneUbo pipeline pragma to sceneInfo to convey possible user-side usage

mentioned in commit 3c8fcf7f

merged