Implement Other Transports

We should implement a few other transports. Most notably right now, the Android AOA transport needs refactored and brought up to speed on the latest interface design. But more interestingly, we could implement a WebUSB protocol that allows clients to visit the webpage (like a real hosted one), and just plug in! WebUSB [does not have wide availability yet though](https://caniuse.com/webusb).

Look for existing transport implementations in the codebase to understand the interface design. Research Android AOA (Accessory Protocol) and WebUSB specifications. The work involves refactoring the Android transport and implementing a new WebUSB protocol layer. Testing will require physical Android devices and a browser with WebUSB support.

Scritto dal modello di indicizzazione a partire dal testo della issue.