Exposing Unifi Chimes for volume control
**Is your feature request related to a problem? Please describe:**

Unifi does not offer scheduled control over the UP Chime. Via configuration you can manually set the volume via the Protect app, but I want to automate this, effectively disabling sound during the night.

The chime is linked to my G4 Doorbell.

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

The ideal goal would be a switch (or brightness control) that can set the Chime volume, I will not be disturbed by callers in the middle of the night.
Nice to have: an updated brightness control, according to the latest value (when another device changes it outside the home ecosystem).

**Describe alternatives you've considered:**

I can try to use another plugin with the Homebridge.io ecosystem, and try to setup the required HTTP REST+JSON requests. 
_But as authentication and a general implementation for Unifi already exists here, I thought to extend it._

**Additional context:**

I want to have a scheduled time this Chime goes 'off' during a set time in the night, via Apple home controls, so I will not hear it when I or any other of the family are asleep.

I am a software-engineer, and have already made a mock using CURL HTTP command with JSON payload to set the Chime volume directly (this works perfectly), examples below.

Let me know what you think of this feature, It would help me out a lot.

List all chimes
```bash
$ curl -k -X GET https://nvr-host/proxy/protect/api/chimes --cookie "*****" -H "X-CSRF-Token: ****"
```

Set Volume to n-percentage
```bash
$ curl -k -X PATCH https://nvr-host/proxy/protect/api/chimes/<chime.id> -H 'Content-Type: application/json' -d '{"volume": n}' -v --cookie "*****" -H "X-CSRF-Token: ****"
```
