[FEATURE REQUEST] add code-generating activity

[ravilov]

I was wondering if it'd be possible to add a published manifest activity that would accept some basic parameters (type, data, options) and show a screen with generated code. Something like type=QR, data=nobody@example.com, size=256x256,options=whatever=123&other=abc. Even better if the activity could also respond to a custom URI scheme (codegen://qr/some+data?opt1=value&opt2=something).

The functilnality is already there, available after a code is scanned. Just need to expose it for direct invocation.