Add "data_required=True" check into heat rest api
Add "data_required=True" check into heat rest api

To validate heat templates it need pass parameters.
Add this check into rest/heat.py to discover error as early as possible

Change-Id: I55468535066104f05d85b146a93023f3a90dcf2d

coreycb/horizon,BiznetGIO/horizon,noironetworks/horizon,coreycb/horizon,bac/horizon,NeCTAR-RC/horizon,BiznetGIO/horizon,wolverineav/horizon,NeCTAR-RC/horizon,BiznetGIO/horizon,sandvine/horizon,ChameleonCloud/horizon,yeming233/horizon,ChameleonCloud/horizon,ChameleonCloud/horizon,NeCTAR-RC/horizon,wolverineav/horizon,wolverineav/horizon,noironetworks/horizon,BiznetGIO/horizon,sandvine/horizon,openstack/horizon,coreycb/horizon,bac/horizon,yeming233/horizon,bac/horizon,noironetworks/horizon,yeming233/horizon,wolverineav/horizon,openstack/horizon,noironetworks/horizon,coreycb/horizon,bac/horizon,openstack/horizon,sandvine/horizon,NeCTAR-RC/horizon,sandvine/horizon,yeming233/horizon,ChameleonCloud/horizon,openstack/horizon