Support the configuration inputs from the new MCCI BSPs

[terrillmoore]

Add support for the following networks:

• Helium
• machineQ
• Senet
• Senra

And software stacks

• Actility
• ChirpStack (see Support for chirpstack.io (ex Loraserver) #135)

And a generic entry.

• Generic

For regions where subbands make sense (US, AU, CN470), allow the default subband for join to be set via a compile option.

For some networks, this might allow ABP to configured as well, but that's got to be added case-by-case.

[terrillmoore]

machineQ was already supported, but getting to it required editing code. We'll support the legacy config scheme, but the names chosen for the MCCI BSP use LMIC rather than LoRaWAN.