Integrate with Piral Feed Service

[FlorianRappl]

It should be quite cool to be able to log into (different, i.e., the public one/s as well as private / on-premise instances of) the Piral Feed Service.

VS Code can safely store the retrieved token allowing a personalized session that could be used to interact with the feed(s) such as changing rules, toggling pilets, ... - or having the interactive publish done very conveniently (w/o even logging in as one is already logged in).

See:
https://github.com/microsoft/vscode-extension-samples/blob/main/authenticationprovider-sample/README.md