Introduce top-level sound controller and add volume control to game options

[Frizi]

The sound controller is now application-wide, so no sound glitching should happen on route changes. Sound can also be force-stopped per route, which is used on the home screen. The options (volume, mute, game sped) are persisted throughout the session and in localStorage.

That change also includes the "layout" attribute based styles, for now used on the options screen.