Access to maxscale status/config from within the database cli

This is a request to expose some status and config variables of maxscale from within the database cli (mariadb/mysql/etc). The general idea is to log in to the database through the maxscale instance, and while within that database cli, commands could be issued that would return status values from the overlying maxscale instance.

example

$> mariadb -u username -h maxscale-host -P 4006

MariaDB [(none)]> show maxscle status like 'causal_r%';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| causal_reads | ON    |

+---------------+-------+

1 row in set (0.005 sec)

This could allow for SkySQL clients to be able to view maxscale information.