Nodes-grid quadrilaterals

To create a grid of quadrilaterals from a cloud of 3D nodes. The user will be asked for the cell size.

The z of the grid will be extrapolated averaging a collection of neighbor nodes.

If the checkbox "Far points set nodata" is set, then grid points further of the distance specified will be set to a special nodata value (-9999 usually) , and won't generate grid quadrilaterals