Implement op-geth's DA throttling in op-reth

[alfonso-op]

A change was recently made to op-geth to enable DA throttling through a new RPC PR.

This feature should also be implemented in op-reth for parity to support chain operators who may want to run a mixture of op-geth and op-reth sequencers.

[Dhir0808]

I'd like to work on implementing the DA throttling RPC functionality in op-reth. Here's my understanding and proposed approach:

1. The implementation will mirror op-geth's recent RPC changes, adding two new methods:

   • eth_setDAGasPrice
   • eth_getDAGasPrice

2. Key components to implement:

   • Add new RPC endpoints to the existing eth namespace
   • Implement DA throttling manager to handle gas price controls
   • Integrate with transaction pool management for throttling logic
   • Add appropriate tests for both RPC functionality and throttling behavior

3. I'll ensure feature parity with op-geth to support chain operators running mixed op-geth/op-reth sequencers.

I have experience with Rust and implementing RPC endpoints. Would you like me to start with a draft PR focusing on the RPC interface first, or would you prefer a different approach?