Add MultipleEntryDataWithSchema interface
We are sharing essentially the same code in both JSON and XML
parsers, where we really to make this common code exposed from
appropriate NodeDataWithSchema.
Centralizing the interface contract and implementations allows us
to ditch external users of CompositeNodeDataWithSchema.addChild(),
which is now deprecated.
Change-Id: I5aca3d3eecba3f9e6ffee4b9ee15e70afa47aed6
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit
94336a79d974543e50cd5e9047d6bd148e4ddbda)