'crinkle' PlotOverLine Feature Request

Plot Over Line samples regularly along the line. We frequently have requests to only sample at grid intersections or to snap to a point in an unstructured mesh. "instead of plotting uniformly separated points, plot just points on the mesh" So for instance on this grid: If it were point data, either interpolate at the line intersections or snap to the line closest(?). If it were cell data take the sample at the midpoint of the line within the line-cell intersection? Perhaps the details could be ironed out in the discussion, but the sampling should be based on the grid: A "crinkle" option to the PlotOverLine. @boonth @ethan.stam @cmbiwer