bug: transaction_index serialized to Null

[ftupas]

Bug Report

Kakarot RPC version: 9828d4a

Current behavior:

As describe in this issue paradigmxyz/reth#4260, transaction_index gets serialized to Null so when we run forge scripts, we get an error. The plan is to make it into u64 in this pr so we will have to set it to 0 for now and write a todo to have an accurate value for it.

Expected behavior:

Should serialize/deserialize properly and forge script runs successfully.

Steps to reproduce:

1. make katana-rpc-up
2. forge script scripts/PlainOpcodes.s.sol --rpc-url http://127.0.0.1:3030 --broadcast

Related code:

Failure on receiving a receipt for 0x03ce61d5642cbb216ce62dbabdc5ad84c290760dbbc138cd9683e97c8e452949:
Deserialization Error: invalid type: null, expected a (both 0x-prefixed or not) hex string or byte array containing between (0; 8] bytes at line 1 column 111. Response: 
{
  "transactionHash": "0x03ce61d5642cbb216ce62dbabdc5ad84c290760dbbc138cd9683e97c8e452949",
  "transactionIndex": null,
  "blockHash": "0x02c9e63a66f5b91714f9b132df3cce6da9866e5c1d6ee54598c555a202b2101b",
  "blockNumber": "0xe",
  "from": "0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266",
  "to": null,
  "cumulativeGasUsed": "0xf4240",
  "gasUsed": "0x7a120",
  "contractAddress": "0x5fbdb2315678afecb367f032d93f642f64180aa3",
  "logs": [],
  "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  "status": "0x1",
  "effectiveGasPrice": "0xf4240",
  "type": "0x0"
}

Other information: