Menu UI Overhall

All the buttons in the pause menu now have little icons. That makes them easier to recognize.

I also added a real playback control for the music player in the pause menu.

Next will be a mission selection screen where you can select levels that you already unlocked. I will also add an overview of the best trophies that you collected per mission in a single play.

I also still need to add the package pickup for the third mission trophy.