introduce Storage abstraction interfaces
use Storage i/f to load zip and 7z archives, cdi/cue/gdi/chd media,
cheats and to find custom textures.
Use android file picker to add storage. Request persisted access perms.
jni helper classes.
Issue #813
Correct handling of non square images
Improve search for arcade game names
Retrieve other images if no boxart (titlescreen, screenshot)
Changed some arcade rom names to more friendly ones