Remove manual adjustment of start_index

[veenstrajelmer]

Is implemented here:

dfm_tools/dfm_tools/meshkernel_helpers.py

Lines 191 to 198 in 1d0ed3d

	#convert 0-based to 1-based indices for connectivity variables like face_node_connectivity
	xu_grid_ds = xu_grid.to_dataset()
	xu_grid_ds = xr.decode_cf(xu_grid_ds) #decode_cf is essential since it replaces fillvalues with nans
	ds_idx = xu_grid_ds.filter_by_attrs(start_index=0)
	for varn_conn in ds_idx.data_vars:
	xu_grid_ds[varn_conn] += 1 #from startindex 0 to 1 (fillvalues are now nans)
	xu_grid_ds[varn_conn].attrs["start_index"] += 1
	xu_grid_ds[varn_conn].encoding["_FillValue"] = -1 #can be any value <=0, but not 0 is currently the most convenient for proper xugrid plots.

Todo:

• support writing of netfile with start_index=1 and _FillValue!=-1 xugrid#119
• await new release (0.12.1)
• update minimal xugrid version
• remove this part of the code
• test grid generated by test_meshkernel_to_UgridDataset() by opening it in interacter and running the model
• update issue link in comment to Merge projected and is_geographic xugrid#187
• update whatsnew