Transaction submission from multiple EOAs in the same batch

Now that we have updated the weights for EVM-related metering, we can consider putting transactions from different EOAs in the same batch. This will improve the throughput of the [BatchTxPool](https://github.com/onflow/flow-evm-gateway/blob/main/services/requester/batch_tx_pool.go#L183-L196).
We need to find the max gas limit that can fit in a single Cadence transaction for that.