Create a clean_user_cache() function / fix refresh_user_details()
|Reported by:||Denis-de-Bernardy||Owned by:||ryan|
refresh_user_details() potentially leaves garbage in the cache, in that it merely deletes two buckets:
wp_delete_user(), by contrast, additionally deletes:
There are several other occurrences where the same applies, in WP. We should refactor the area of WP a little and introduce some kind of clean_user_cache() function.