Allows to perform a have content operation providing a connection that have being received.
This fucntion performs the same tasks as afgs_command_have_content function but providing a AfGsConnection object that was reserved by using the following functions:
|db_connection ||The connection where the "have-content" operation will be performed.|
|cmd_string ||The command string represening the command to exeucted, using a printf-like format.|
- TRUE if the command executed have content, FALSE if not.