[Discussion] Implementing Thread with Homebridge
### Current Situation

Currently, accessories can connect and be exposed to HomeKit using a variety of different protocols (API, LAN, Bluetooth, etc). However, Thread is not something that is currently supported in the base image. In addition, despite the Homebridge server acting as a hub in HomeKit, it does not interact with devices using Thread in any way and cannot act as a border router nor assume the role of a Thread "Leader" in the event that another Thread border router fails.

### Proposed Change

I propose adding Thread support to Homebridge. I am not completely sure how plugins would interact with accessories over Thread, as it would require the accessory to also support Thread. However, I do think that Thread support should be baked in to the base image for other plugins to use. In addition, baking Thread directly into Homebridge opens the possibility of using the Homebridge server/container as a border router that can act as "Leader" of a local Thread network. I believe that this can be added using an open-source implementation of Thread such as [OpenThread](https://openthread.io). This can allow the Homebridge server to strengthen existing Thread networks, such as extending the range of the mesh network and providing a fallback border router in the event that other Thread devices go offline.

Overall, I think that adding support will be an excellent step into the future, especially with many existing devices already implementing Thread support. It will also help improve network response times and decrease congestion, especially with users with an extremely large amount of HomeKit devices on their network. Thread is based on IPv6, so users should not need new adapters for their installation other than a network that supports IPv6. This implementation also opens up Homebridge to many other platforms through [Matter](https://csa-iot.org/all-solutions/matter/) (although it should be noted that Matter runs on a combination of Thread, Wi-Fi, and Bluetooth).

I intend for this issue to be a discussion hub for all things Thread-related with Homebridge, if this implementation is possible. Thank you!

### Additional Resources

1. [Thread (Wikipedia)](https://en.wikipedia.org/wiki/Thread_(network_protocol))
2. [Thread for Developers](https://www.threadgroup.org/What-is-Thread/Developers)
3. [OpenThread](https://openthread.io)