BUG #14897: Fix periodic boundary issues with vtkNetCDFCAMReader.

vtkNetCDFCAMReader did not deal with periodicity of the domain
correctly. There were cases (as demonstrated by the report BUG) where
the cells we incorrectly split. Fixed the code to be more robust to the
potential ways in which the points in the cells are defined. Also
includes some performance tweaks e.g. using vector instead of map.

This deprecates the SetCellLayerRight/GetCellLayerRight API on the
reader. This API is no longer needed since the reader makes an informed
decision when deciding which side to place the cells that overlap the
periodic boundary.