Add Columns and Modify Column Type in system.storage_policies Table

Why it matters

This update enhances the system.storage_policies table by providing additional details about storage policy behavior, such as whether TTL moves are performed on insert and how data load is balanced across volumes. Changing volume_type to Enum8 improves type safety and clarity for volume type representation.

How to use it

Users can query the updated system.storage_policies table to access the newly added perform_ttl_move_on_insert and load_balancing columns directly. The volume_type column now uses the Enum8 type automatically, requiring no manual changes when querying.