subscriber location rewards

[andymck]

Linked proto PR:

helium/proto#345

Adds support for subscriber location rewards

Linked HIP: https://github.com/helium/HIP/blob/main/0079-mobile-poc-mappers-rewards.md
Linked issue: #422

TODO:

• plug in carrier key API usage, when API is available
• remove local debug TODOs
• merge proto 345 and update deps
• squash commits

Tested locally end to end, example of subscriber reward outputted :

{
"start_period": 1686052372,
"end_period": 1686138856,
"reward": {
"SubscriberReward": {
"subscriber_id": [
115,
117,
98,
115,
99,
114,
105,
98,
101,
114,
95,
120
],
"discovery_location_amount": 30000000
}
}
}