ref (background): added proper handling of update/install events
ref (background): added proper handling of update/install events

- On install, the default settings are set to the storage.local.
- On update, if the previous version was < 1, the previous settings are
  completely cleared and the default settings are added. This is to
  make sure that the previous settings dont conflict with the new
  settings. If the update was from version 1 and above then the old
  settings are preserved and new ones are added.

lap00zza/9anime-Companion,lap00zza/9anime-Companion,lap00zza/9anime-Companion