[token-server] Adjustments to rate limits

Summary:
Depends on D16841

For XEC rewards, adjust rate limits so IP addresses are limited to 1 reward every 7 days

For token rewards, adjust rate limits so IP addresses are limited to 3 rewards every 24 hrs

Test Plan: npm test, proofread limiter objects in config

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D16843