Support for filtering `txs` dataset with function signature, as well as optional calldata decoding

[cool-mestorf]

Just like the --event-signature flag, cryo would be able to take a --function-signature "transfer(address)" flag to filter transactions with certain function signature, and furthermore parse their calldata according to given parameter types. It may take optional argument ex. --raw-function-signature "0x1a695230" for filtering only.

[sslivkoff]

this is a good idea