Support G4 Doorbell Pro Package Camera

**Is your feature request related to a problem? Please describe:**

I would like to be able to view the package camera for my Doorbell Pro.

**Describe the solution you'd like:**

A second HomeKit camera of the package camera (it is available as a separate RTSP stream).

**Describe alternatives you've considered:**

The package stream isn't actually supported in the iOS app so I can only view it on web right now.

**Additional context:**

Product page is here:

**REDACTED - PLEASE DO NOT POST NON-PUBLIC UBIQUITI LINKS HERE**
