review crash recovery scenarios relating to file creation and renames

This issue relates to a comment in code being refactored here: https://github.com/apple/foundationdb/pull/12967

The comment seems to be overly specific about one of the specific scenarios where a crash can cause trouble.
In general a crash after any update to persistent state is something that should be handled.
This bug^H^H^Hissue is to look at this logic and ensure that testing covers crash recovery after every persistent update in the code path above.

Start with the code and comment changed by pull request #12967, then trace the file-creation and rename path through each persistent-state update. Review the existing crash-recovery coverage and extend it so every persistent update in that path is tested for recovery after a crash; done means the relevant scenarios are covered.

Written by the indexing model from the issue text.