vtkDIYGhostUtilities: loosen bounding boxes

If the input data sets have loose point positions (i.e. points across partitions that are supposed to match don't actually match), the ghost cells generator fails at binding those points. This is not a problem if the input does not have global ids. However, if it has global ids, points then match. If a partition A has a bounding box that doesn't include some neighbor's points while this neighbor's bounding box includes the ones of A, then, if some of those point's global ids match, there is a conflict on the topology between partitions, and, as a consequence, the process will fail. The issue is the lack of symmetry between blocks while running the algorithm.

To avoid such events, each bounding box of each partition is now inflated by a lot (0.1% of its max width). This will include more points when checking which points are to be transfered, but this will include any "decent" situation. From now on, the filter will fail for points whose precision is lower than 0.1% of the bounding box width with global ids attached to the points. Such an input can be deemed ill-formed.

Adresses paraview/paraview#21228 (closed)