Summary

We should add a debug option to wiredtiger_open that would retain a certain number of old contents of the turtle file.

Motivation

We already have a debug option for keeping a certain number of old checkpoints; if we add this new option, it would allow us to replace the contents of the current turtle file and restart the database from the various points in the past.

For example, this would have been very useful when debugging WT-13252, in which case RTS did not run correctly after the database restarted. We had old versions of all data from before the database restart hidden in the .wt files, and if we also had the old version of the turtle file, we would have the entire database state from before restart, which would have allowed us to run RTS on it again to try to reproduce the issue.