Feature Request: Support ALTER STORAGE SERVER ... OWNER TO ... and COMMENT ON STORAGE SERVER

In the current version of Cloudberry, it is not possible to modify the owner of a `STORAGE SERVER` object or add a descriptive comment to it after it has been created. The corresponding DDL commands, `ALTER STORAGE SERVER ... OWNER TO ...` and `COMMENT ON STORAGE SERVER ...`, are not supported and result in a syntax error.

This limitation creates a gap in the database's object management capabilities. For most other database objects (like tables, functions, etc.), it is standard practice to allow modification of ownership and comments, which is crucial for database administration, security, and documentation.

Start by tracing the parser and object-management paths for ALTER STORAGE SERVER ... OWNER TO ... and COMMENT ON STORAGE SERVER ..., since no implementation files or tests are named. Done means both statements parse successfully after creation and correctly update the storage server owner and comment, with coverage for each command.

Written by the indexing model from the issue text.