replace remove xu noncontiguous with mk disconnected regions

[veenstrajelmer]

Was implemented in meshkernelpy 3.0.0 (Deltares/MeshKernelPy#87) with mkernel_mesh2d_remove_disconnected_regions.First wait on #563

This can potentially replace this part in dfmt.meshkernel_to_UgridDataset() (and move it outside function):

dfm_tools/dfm_tools/meshkernel_helpers.py

Lines 132 to 146 in c110845

	def xugrid_remove_noncontiguous(grid):
	#based on https://deltares.github.io/xugrid/examples/connectivity.html#connected-components
	#uses https://docs.scipy.org/doc/scipy/reference/sparse.csgraph.html
	#TODO: maybe replace with meshkernel?
	uda = xu.UgridDataArray(
	xr.DataArray(np.ones(grid.node_face_connectivity.shape[0]), dims=["face"]), grid
	)
	labels = uda.ugrid.connected_components()
	counts = labels.groupby(labels).count()
	most_frequent_label = counts["group"][np.argmax(counts.data)].item() #find largest contiguous part
	labels = labels.where(labels == most_frequent_label, drop=True)
	grid = labels.grid
	return grid
	if remove_noncontiguous:
	xu_grid = xugrid_remove_noncontiguous(xu_grid)