PadListDataCollate to support inverse MetaTensor

[wyli]

PadListDataCollate.inverse should support MetaTensor (as it's used in test time augmentation)

MONAI/monai/transforms/croppad/batch.py

Lines 114 to 118 in 99b9dd7

	for key in d:
	transform_key = InvertibleTransform.trace_key(key)
	if transform_key in d:
	transform = d[transform_key][-1]
	if not isinstance(transform, Dict):

also the test cases are incomplete:

MONAI/tests/test_pad_collation.py

Lines 97 to 106 in 99b9dd7

	loader = DataLoader(dataset, batch_size=10, collate_fn=collate_method)
	# check collation in forward direction
	for data in loader:
	if t_type == dict:
	decollated_data = decollate_batch(data)
	for d in decollated_data:
	PadListDataCollate.inverse(d)
	if __name__ == "__main__":