use TransactionSignedEcRecovered in the builder so that signer recovery is not necessary internally.
in the future there will be some conversion from some RPC representation of a bundle, and at that point, or some intermediate step before the builder sees it, we should perform the signer recovery for each transaction within the bundle.
if we decide against this and continue to do signer recovery within the builder, then it should be done at the top level, so that each build job does not need to repeat the work
use
TransactionSignedEcRecovered
in the builder so that signer recovery is not necessary internally.in the future there will be some conversion from some RPC representation of a bundle, and at that point, or some intermediate step before the builder sees it, we should perform the signer recovery for each transaction within the bundle.