[Feature] Add a feature to use quick share on system share menu

[banothsidhu]

Add AirSync's Quick share to system share extension for easy sharing .

[sameerasw]

I have been trying this for a couple of times but idk I keep failing. Maybe because the app is not sandboxed but the communication between the app and the extension often fails....

I'll take a look again soon

That's why I added the service entry so far... Since it doesn't rely on sandboxed communication. But the share extension would be better.