Preconf RPC improvements: Track the commitments and handle slashes #729

Currently the RPC service only checks that all providers have committed or if the transaction is in the block to verify. But we should also track if the commitments were opened, how much decay happened? Do we need to refund users for the decay etc. Also if the commitments were not honoured, the providers could be slashed and this should result in some kind of compensation for the users sending transactions.