`HoVerNetNuclearTypePostProcessing` not working with default arguments

[bhashemian]

Describe the bug
HoVerNetNuclearTypePostProcessing not working when output_classes=None and return_centroid=False, which are the default arguments for this transform.

[wyli]

isn't this test case cover what you described?

MONAI/tests/test_hovernet_nuclear_type_post_processing.py

Line 52 in 9adfb4b

TEST_CASE_2 = [seg_postpprocessing, {"return_centroids": False, "output_classes": None}, [image]]

[bhashemian]

isn't this test case cover what you described?

MONAI/tests/test_hovernet_nuclear_type_post_processing.py

Line 52 in 9adfb4b

TEST_CASE_2 = [seg_postpprocessing, {"return_centroids": False, "output_classes": None}, [image]]

@wyli, the test doesn't seem to check the type segmentation map. It should be fixed too.