Scoru,Node: take payloads instead of messages during simulation

Context

Contributes to #5688 (closed)

Built on top of !8869 (merged)

For the context: we want to give unsigned transactions to the EVM rollup that can be sent to the rollup node simulation. A good way to ensure these simulation messages happen only in simulation is to give a non existant internal message tag, which will be prohibited by the protocol at all time. The only change in the rollup node we need is to allow to take serialized messages instead of external message payloads.

Manually testing the MR

I modified in a commit to remove the EVM rollup so it panics on a given tag. If you run the associated "simulation" test you'll see that the kernel panicked and did not advance. Removed the commit.

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR