Highlight which pieces of byte code actually get loaded into ROM

[OlivierBBB]

For soundness reasons on the state manager side (and for marginal performance gains) we may want to tag those accounts whose byte code actually get loaded into ROM. Note. It should be relatively rare that you touch accounts without executing their code (e.g. via BALANCE or EXTCODEHASH/EXTCODESIZE) whence the marginal performance gain on the prover side.

This resulted from a discussion with the prover team on the arithmetization <> prover interface for byte code.