[Feat.Req] Deny senders over a certain amount of unaggregated fees

[aasseman]

Problem statement
Implement a maximum unaggregated fees trigger (that is larger than the trigger for RAV request) over which business with a sender is to be denied.

Expectation proposal
Adding:

• A new unaggregated fees trigger for sender denial
• A sender deny list in DB
• PG notifications to quickly inform the indexer-service instances of adding/removal from the deny list