Support for multiple radio interfaces

[code8buster]

There is at least one board in the protobufs with two SPI Ebyte modules on board, selectable via CS/NSS pin. (disasterradio v3 DR_DEV)
Currently, there is no way to use both simultaneously, nor any logic in the Router to decide which module a packet should be sent to, or track which module a packet came from.

thebentern and sachaw suggested I create a tracking issue. To enhance the project in this way would likely require changes to RadioInterface, Router, and a slew of other core modules.

[Krezalis]

It can be a very helpful functionality at repeater node 433/868. No need to use two ESP and an additional IC to route messages via UART.

[m-anish]

This would be a very nice feature to have. :)

[Ccz119]

I can think many uses for this !