Provide more useful data in network join notifications

When a device new to my Eero network joins it (or a device that hasn't been on it in a while) I get a pop-up notification from the app on my Android phone.

The message says something like:

A new device has joined your network "Apple Inc"

This is a nice gesture, but it could be a lot better.  The app could (and should) expose more identifying data than just what the MAC address is telling Eero.

Eero already has this data stored, often in two places:
    Some devices have been manually named by the user within the Eero app.
    Some (most) devices self-report a hostname.

So the desired behavior change is for the pop-up notification to say

"A new device has joined your network: %devicename%"

Where %devicename% is one of the following, in order of availability:

1. The name that was previously manually assigned by the user within the Eero app if one exists (ex: "Amy's iPhone 11")
2. The self-reported hostname of the device (ex: "Amys-iPhone") if one exists
3. If all else fails, stick with the current system, reporting on MAC address data (ex: "Apple Inc")