core: Change connect/disconnect storage commands to type agnostic

As a part of the effort to remove the type of storage pool the connect
and disconnect host to storage command were changed to ignore the specific
type of the connection and instead create a map of all connections divided
by type and connect/disconnect to all type by type

Relates-To: https://bugzilla.redhat.com/1038053
Change-Id: I07a7fb8af9ce89a38b51cdb07a43a15f9c13f839
Signed-off-by: Tal Nisan <tnisan@redhat.com>