FR: udp arbitrary data with actions and triggers

[nagyrobi]

Let's have a udp.data_transmit action to simply pass arbitrary data to another node (supporting the addresses: field).
An on_data_received trigger (under udp: > providers: > - name to know which provider to expect the data from).

Support the same types as the sensors, eg. binary, float, string (maybe integer? specify type: on both ends maybe like globals are?). Print an error to the log when the data is too big. (adding a warning in the docs)

Eventually configurable, on_data_received should only trigger for data sent by data_transmit from the provider, not the sensors. Moreover, we could support accepting and sending raw messages, to possibly integrate with third party systems communicating via UDP (eg. BrightSign)

Possible use case would be for transmitting actions, not states. For example to relay IR remote signals to a blaster in another room. Or to transmit button presses. Or in conjunction with key_collector transmit the collected keys as string to another node in an encrypted form (say you have an alarm panel in lvgl near the door, but the alarm itself is another node). Also the second use case (covers) from #112 could be less cumbersome if we had this.

[nielsnl68]

Yes, that is something i can use as well.