Do not serialize and fetch abi when overriden

[potuz]

When overrides is passed, the data parameter already overrides the payload, which unnecessarily calls to serialize the transaction and also to fetch the abi from etherscan and 4byte as these will be overwritten.

[potuz]

If this change is to be considered, I would suggest to explicitly export fetchDecoder since someone that wants to pass an override may want to get the decoder before doing so.