Allow definition of volume_priority in storage_configuration

Why it matters

This feature enables users to specify the priority of different storage volumes, improving data placement and management by allowing more fine-grained control over which volumes are preferred when writing or reading data. It helps optimize resource utilization and performance based on storage hierarchy or hardware characteristics.

How to use it

Users can set the volume_priority attribute within the storage_configuration section of the ClickHouse configuration file. This value determines the priority order of volumes in storage policies and influences the order in which data is placed or accessed.