Add interpolate/ramp fill color to MultiPolygonZ/PolygonZ according to z value.

[qsavoye]

Feature description

When z value are set up for polygonZ vertices, QGis would propose to users the possiblility to fill color (ramp or interpolated) according to the polygon elevation in Symbology tab.

Interval for ramp color could be set by the user or automatically detect by QGis between the minimum and maximum z value.

Maybe QGis could do the same things with M value.

Additional context

No response