chore(util): Add reth payload util

[TheDhejavu]

Resolves: #12533

• Added a new reth-payload-util crate within the payload module that contains shared utilities, allowing transaction-pool to use these utilities without creating dependency cycles.
• I also discovered that many components are tightly coupled with the transaction pool module, which explains the concentration of changes there. We should consider refactoring the transaction pool to better separate concerns, especially for functionality that could be reused elsewhere without creating dependency cycles.

For example, this code remains in transaction pool due to its dependencies:

reth/crates/transaction-pool/src/pool/best.rs

Line 213 in 7bd7c37

pub struct BestPayloadTransactions<T, I>

[mattsse]

good first step, I'm fine with inverting the dependency and move more txpool related things to payload-util