We have a lot of scattered assertions about the state of a restore node after magic restore. We use these in our targeted tests to ensure things like the stable timestamp and oldest timestamp are set correctly, there are an expected number of ops in the oplog, etc. We should try to consolidate these into a clean API that tests can use to ensure the state after a magic restore is correct.

We could create a `afterRestoreAssert` function that would check all the relevant assertions.