Added api entry v1/node/<uuid>/action to allow user to post reset
action to composed node. The available reset type contains
Power On/Off, Force Shutdown/Restart, etc, which may vary because of
different podm.
Partially-Implements blueprint node-action
Closes-Bug: #1659932
Change-Id: Idb23bdde02318c70e046e92dd1d474cba54c645e