Add tests for CP SRC-20 Tokens

[reinamora137]

Need to add in the data key with the counterparty data to validate the flow through parse_stamps in particular.

[reinamora137]

These will look something like this with the stamp key which is what comes in from blocks.py

    {
        "description": "SRC-20 token transfer uint64 dec.dec, scenario No.44",
        "stamp": "{ CP Trx details, asset_longname, supply, etc, etc}", 
        "expectedOutcome": {
            "stamp_success": True,
            "src20_success": True,
            "message": "token previously deployed"
        },
        "source": "1SourceAddr",
        "destination": "1DestAddr",
        "btc_amount": 0.0,
        "fee": 0.0,
        "decoded_tx": "{}",
        "keyburn": 1,
        "tx_index": 0,
        "block_index": 0,
        "block_time": 0,
        "is_op_return": False,
        "valid_stamps_in_block": [],
        "processed_src20_in_block": [],
        "p2wsh_data": None,
        "tx_hash": "utest44"
    },