Introduce trait for OpTransaction

[mattsse]

we have extra helpers for deposit functions:

reth/crates/primitives/src/transaction/mod.rs

Lines 485 to 519 in 0b63972

	/// Returns the source hash of the transaction, which uniquely identifies its source.
	/// If not a deposit transaction, this will always return `None`.
	#[cfg(feature = "optimism")]
	pub const fn source_hash(&self) -> Option<B256> {
	match self {
	Self::Deposit(TxDeposit { source_hash, .. }) => Some(*source_hash),
	_ => None,
	}
	}
	/// Returns the amount of ETH locked up on L1 that will be minted on L2. If the transaction
	/// is not a deposit transaction, this will always return `None`.
	#[cfg(feature = "optimism")]
	pub const fn mint(&self) -> Option<u128> {
	match self {
	Self::Deposit(TxDeposit { mint, .. }) => *mint,
	_ => None,
	}
	}
	/// Returns whether or not the transaction is a system transaction. If the transaction
	/// is not a deposit transaction, this will always return `false`.
	#[cfg(feature = "optimism")]
	pub const fn is_system_transaction(&self) -> bool {
	match self {
	Self::Deposit(TxDeposit { is_system_transaction, .. }) => *is_system_transaction,
	_ => false,
	}
	}
	/// Returns whether or not the transaction is an Optimism Deposited transaction.
	#[cfg(feature = "optimism")]
	pub const fn is_deposit(&self) -> bool {
	matches!(self, Self::Deposit(_))
	}

these should be converted into a trait on https://github.com/alloy-rs/op-alloy and implemented on

https://github.com/alloy-rs/op-alloy/blob/56f636e8f624164fdea9c5356ee59b40af8f5e9d/crates/consensus/src/transaction/deposit.rs#L15-L15

[hoank101]

hi @mattsse Can i work on this?