#26301: [hiero] way to reset a global cache per-export

The resolve hook is called tons during an export, so expensive resolve results need to be cached. There currently isn't a hook available that run pre-export where that cache could be cleared
The name feels odd after looking at it for a while.  It reflects the code base rather than the usage.  Would something like "hook_pre_export" make more sense and be more indicative of what the hook will do?