Pass geotop layers to get_combined_layer_models

[dbrakenhoff]

Allows for using different option for parsing paleochannels without having to run all methods separately.

Usage:

geotop = nlmod.read.geotop.get_geotop(extent)
gt_layered = nlmod.read.geotop.to_model_layers(geotop, method_geulen="add_to_layer_above")

nlmod.read.regis.get_combined_layer_model(extent, use_regis=True, use_geotop=True, gt_layered=gt_layered)

[rubencalje]

Does this have anything to do with issue #420?

[dbrakenhoff]

Does this have anything to do with issue #420?

Indeed it does :)