add eth_sendRawTransactionSync to the node

[TheGreatAxios]

x402 Partner Request: add eth_sendRawTransactionSync to the node.
Why: Reduces latency quite a lot.

References:

• https://docs.chainstack.com/reference/base-sendrawtransactionsync
• https://ethresear.ch/t/halving-transaction-submission-latency-with-eth-sendrawtransactionsync/22482