Reinterpolation of a pointCloud in an area layer without modifying the interpolated field outside (or inside) of the area

For now, we can re interpolate in an area layer but automatically the nodes which are outside (or inside, depending on the choice of the user) the area layer will be put at the default value and the first interpolation will be loosed. If there is already an interpolated field, give the user the possibility to choose a default value or the already inerpolated field outside (or inside) the area layer.