Test support for multiple miners running in parallel

[UpstreamData]

Seen a few reports of being unable to run miners in parallel and query both of them via HASS, I have a few theories on this:

• The hostnames being used as a unique ID could be causing the entities to overwrite each other, as (for example) stock antminers all use Antminer as their hostname.
• MinerCoordinator could be causing issues with multiple miners. I'm not sure how MinerCoordinator is actually handled on the backend of HASS, but if only 1 instance is created and it's expected to handle all miners for the whole hass-miner integration, overwriting coordinator.miner would cause issues.

Based on these, MAC address could be used as a UUID, or if the issue is related to the miner coordinator, there are ways to coordinate all the miners as a list inside that class.

[Schnitzel]

v1.0.0 uses MACs as UniqueIDs now