chore(sdk): define OpTransactionSigned

[emhane]

Closes #11575

• Defines new type OpTransactionSigned, that wraps reth_optimism_primitives::OpTransaction
• Extracts optimism feature gated logic from TransactionSigned impl, into impl SignedTransaction for OpTransactionSigned

[mattsse]

if you stack prs, please reference them, otherwise this makes it harder to navigate

[mattsse]

before we do anything her let's please try to make progress on some abstractions first (#11432)

and validate this against our current primitives types before we introduce new ones.
this is more efficient than working on separate network specific types already.

[emhane]

before we do anything her let's please try to make progress on some abstractions first (#11432)

and validate this against our current primitives types before we introduce new ones. this is more efficient than working on separate network specific types already.

gottcha. this is code is checked out from #11348 (referenced in commit message). it moves the logic in TransactionSigned impl, and removes the optimism feature gate from it.

[emhane]

any idea about the failing test @Rjected @joshieDo @mattsse ?

I'm suspecting it has to do with the OpTypedTransaction not having tx type eip4844, and how reth_codecs::add_arbitrary_tests is implemented.