HIP-991: Permissionless revenue-generating Topic Ids for Topic Operators

[steven-sheehy]

Discussion for https://hips.hedera.com/hip/hip-991

[steven-sheehy]

Prefer ConsensusCustomFee be named TopicCustomFee since the use of consensus is ambiguous without also including topic like ConsensusCreateTopicTransaction has.

[Neurone]

Makes sense to me. If @netopyr agrees, I can send a PR to update the name of ConsensusCustomFee and ConsensusCustomFeeList to TopicCustomFee and TopicCustomFeeList.