rename challenge bypass kafka topics and fix local docker-compose environment

[evq]

currently we use the variables GRANT_CBP_SIGN_CONSUMER_TOPIC and GRANT_CBP_SIGN_PRODUCER_TOPIC. this naming is confusing as each kafka topic ( token sign requests, signed token results ) has both a producer and consumer and it is unclear from the name what the purpose of each topic is. ( e.g. are the roles referring to our perspective or the challenge bypass service's perspective? )

as a result of this poor naming, we have actually confused the two and our docker-compose.yml does not work properly end to end.