test(ctb): Add test for get75PercentThreshold

This change fixes a bug in getNSigners which incorrectly assumed that the length of the signature data
could be used to directly determine the number of signatures provided. This is wrong because contract signatures
append additional data used for the EIP1271 signature validation.

working for approvedHashes

this change is more readable

feat(op-node): Fetch receipts directly from `reth`'s DB

Co-Authored-By: inphi <mlaw2501@gmail.com>

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