resume last listening session on app open

[Dr-Blank]

• idea: show a floating action button to ask if resume book when nothing playing. long press shows last 3 books

• progress syncing may suffer when starting playback directly

refer: advplyr/audiobookshelf-app#854

[Protarios]

Honestly I would prefer direct playback start.
The reason why reselecting after app restart is so annoying is that I usually listen to audiobooks in the car.
Here it really is an issue if I have to unlock the phone, select the audiobook and start play while driving.
It always works for some days to have playback directly starting, then some battery saving or reboot of android kicks in (even though I have disabled all battery saving features for audiobookshelf) and I am back to having to reselect my current audiobook.