Get Nodes Endpoint (support multipel to-level nodes)

Get Node only returns a single node with its children. This limits the top level list element concept as it will only return one node from the list. Add new endpoint Get Nodes to return multiple parallel nodes. This is a new endpoint, do not change Get Node. Possible option for Get Node deprecation.  

A/C:

Same functionality of get Node but returns a list of Nodes which includes parallel nodes.

Ensure that the functionality of get Node is retained