Embassy-net support for esp-hosted-mcu

[antonello-contini-ok]

It seems that Espressif has deprecated the esp-hosted-fg firmware, recommending instead to move to the esp-hosted-mcu project. Unfortunately, the protocol is incompatible with the previous esp-hosted-fg, so I've started working on esp-hosted-mcu support for embassy-net.

For now, I've forked the embassy-net-esp-hosted crate and integrated the new protocol, as well as added a basic signaling system for events coming from the ESP chip (disconnection and heartbeat deadline).

Is this something you'd be interested in merging? If so, what would be the preferred approach for contribution?

[lulf]

I think we might've discussed this in chat already, but stating it here for the record. I think that would be fine, but it should ideally support the existing/old protocol as well. Possibly using a feature flag or something similar.

[nikvoid]

@antonello-contini-ok can you upload your branch? I want to try it out and add AP mode if it is not implemented yet

[antonello-contini-ok]

I think we might've discussed this in chat already, but stating it here for the record. I think that would be fine, but it should ideally support the existing/old protocol as well. Possibly using a feature flag or something similar.

I think that the protocol is different enough to warrant a dedicated repo, i've created a draft PR to show the changes: #5709