sign_with_address_and_signature should take a &T::Signature as the signature type

[jsdw]

Currently sign_with_address_and_signature looks like:

pub fn sign_with_address_and_signature<S: Encode>(
    &self,
    address: &T::Address,
    signature: &S,
) -> SubmittableExtrinsic<T, C> {

I'd propose that it should look like:

pub fn sign_with_address_and_signature(
    &self,
    address: &T::Address,
    signature: &T::Signature,
) -> SubmittableExtrinsic<T, C> {

This ensures that the signature provided is the correct shape, rather than allowing arbitrary and possibly wrong formats to be provided that are only caught later and may lead to obscure errors and such.