Merge topic 'datamodel-source-list' into release

f85a3592 Rendering/OpenGL2: minor style nitpicks
7d7ded55 Rendering/OpenGL2: install vtkCompositePolyDataMapper2Internal
432a5333 Filters/Statistics: install vtkStatisticsAlgorithmPrivate
53074b35 Common/Core: add missing sources
1a4977ed Common/Core: sort source listing
41d864e6 Common/Core: remove duplicate source listings
c90fd892 Common/DataModel: add other missing sources to the library
15af636b Common/DataModel: install vtkCompositeDataSetNodeReference.h
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: T.J. Corona <tj.corona@kitware.com>
Merge-request: !6887