* Add function to open all appendable dense vector storage types
* Add function to find appendable dense storage files without opening it
* Add function to migrate RocksDB dense vector storage into mmap
* Add feature flag and actively migrate on load
* Log number of migrated points
* Add function to open all simple dense vector storage types
* Add test for simple dense vector storage migration
* Use correct column families
* Use more generic feature flag
* Also migrate vector deletes
* Fix review remarks