[Feature request] Dual radio support

[radiof4n]

Dear Meshcore Enthusiasts,
as meshcore is very crowded in dense areas and SX1280 exists, the following proposal:

• add the option for dual radio

companion:

• In dense areas first send with 2.4GHz (companion) and only if there is no repeat heard switch to lower frequency
• In low traffic areas allow to send directly with lower frequency

router:

• allow for dual radio
• In high traffic situtation use 2.4GHz for near-field communication with companions and high capacity link of traffic to other repeaters
• fallback to lower frequencies for long range DMs or in low traffic environments