Implement Table Comments, Closes #23225

Why it matters

This feature enables users to attach descriptive comments to tables, improving schema readability and maintainability by providing contextual information about the table's purpose or usage.

How to use it

Users can add a comment to a table during creation or modification using the COMMENT clause in the CREATE TABLE or ALTER TABLE statements, for example:

CREATE TABLE table_name (...columns...) COMMENT 'This is a table comment';

ALTER TABLE table_name COMMENT 'Updated table comment';