Thin add support for origin_only suspend of thin volumes

Thin add support for origin_only suspend of thin volumes

Pass in the origin_only flag also for thin volumes - but curently the flag
is not used to its best.

FIXME: achieve the state where only  thin volume snapshot origin is
suspended without its childrens -  let's explore whether this may
happen automatically inside libdm (might be generic for other targets).
So the code would not need to annotate the node for this.