KMS-649: PR adds Redis-backed response caching for hot read endpoints (/concepts*, /concept*, /tree*) with a scheduled cache-prime Lambda, plus deployment/runtime updates to support Redis in AWS and local development.

KMS-649: PR adds Redis-backed response caching for hot read endpoints (/concepts*, /concept*, /tree*) with a scheduled cache-prime Lambda, plus deployment/runtime updates to support Redis in AWS and local development. #523