smbstatus: add a connections dictionary

smbstatus: add a connections dictionary

Adds an empty json dictionary under the key "tcons" and adds foreach
connection a dictionary with information to the shares dictionary.

Only print to stdout, if json_output is not set.

Signed-off-by: Jule Anger <janger@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>