Restore AllNodesExtraMapData
Restore AllNodesExtraMapData

Commit a7661065743086961b8ef93056b810e7d2a49eda removed the
all-nodes-config.j2.yaml Heat template. This template had the support
for specifying hieradata to merge into the all_nodes hieradata via the
AllNodesExtraMapData.

This commit restores the merge logic so that the merged hieradata from
the parameter value and the calculated hieradata is rendered in
all_nodes.json.

Change-Id: I890bbef764b6bae7cb71cfedaff2ce17829737fb
Depends-On: Ib3838d404b45ae6684ef7e0aa211cb8015271866

openstack/tripleo-common,openstack/tripleo-common