objective: make omi private cloud sync[1] more useful.

key results:

• listing, playing, and sharing audio files from the app > settings > storage > private cloud sync
• the delete all option, so users can delete all their audio files

please note, the data training program[2] requires the private cloud sync feature, so users should be informed about this when they choose to delete all their audio files. however, they will still have the option to make this choice.

[1]: #3170
[2]: #3172