Pockettube support added

I added the support for the add-on PocketTube, because it was requested, and all the required code was basically already available. However it always creates new profiles for PocketTube and cannot add them to existing ones.

FreeTube-Legacy-Converter v1.0

For everyone who does not want to download and install NodeJs, here are 3 binaries packages with pkg right out of the repository.