Clip: Fix edgeInterpolationIndexToUnique creation bug

Spiros Tsalikisrequested to merge
spiros.tsalikis/vtk-m:fix-clip-edgeInterpolationIndexToUnique-bug into master

This is the correct order:

  1. Copy the existing edges (which include duplicates)
  2. Sort the copies edges
  3. Remove the duplicate edges from the copied edges so that they are unique
  4. Create a edgeInterpolationIndexToUnique map by querying each edge (including duplicates) and find the which unique id they have by looking into the unique copied edges

@vbolea

Merge request reports