This method allows getting basic info about a queried container. It's
based on the lxc-info command-line tool.

Example output:
> ubus call lxc info '{ "name": "foo" }'
{
        "name": "foo",
        "state": "RUNNING",
        "pid": 2946,
        "ips": [
                "192.168.0.124"
        ]
}

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Approved-by: Luka Perkov <luka@openwrt.org>