Added user-level settings to prevent insertions on nearly full disks

Why it matters

This feature addresses the risk of disk full errors during insertions by allowing users to define minimum free disk space thresholds. It helps avoid insertions on disks that are almost full, thereby improving system stability and preventing potential data corruption or failures.

How to use it

Users can configure these settings at the user level to specify the minimum free disk space required to allow insert operations. For example, set min_free_disk_bytes_to_perform_insert to define the minimum number of free bytes needed before an insert can proceed, and min_free_disk_perform_to_throw_insert to specify when an insert should be rejected due to insufficient disk space.