Add system.dropped_tables for tracking incompletely removed dropped tables in Atomic databases

Why it matters

This feature helps users monitor tables that are in the process of being dropped but remain physically present in the database, providing insight into delayed or pending table removal operations and aiding in database maintenance and troubleshooting.

How to use it

Query the system.dropped_tables table using a SELECT statement to view information about tables dropped from Atomic databases but not yet completely removed, for example:

SELECT * FROM system.dropped_tables;