Support TransactionExtension

[pgherveou]

PR http://github.com/paritytech/polkadot-sdk/issues/3685 introduced a new TransactionExtension trait.

These new extensions should be more flexible than its predecessor SignedExtension and should let us write custom logic to define custom origin authorization. This should be used to authorize Ethereum transactions, instead of the current pipeline that wraps the UncheckedExtrinsic trait and introduces a custom Checkable implementation. This change will result in a fairer weights to extract the signer and decode the ethereum transaction, and should make the integration of the ethereum compatibility layer less invasive and easier to integrate in the runtime.

[smiasojed]

@pgherveou Is it a transparent change or is there any action needed from the Foundry or Remix side?

[pgherveou]

yes this mostly tech debt / implementation details should not impact upstream dependencies