Check that the two split dicts have the same names and num_shards.

def check_splits_equals(splits1, splits2):
  """Check that the two split dicts have the same names and num_shards."""
  if set(splits1) ^ set(splits2):  # Name intersection should be null
    return False
  for _, (split1, split2) in utils.zip_dict(splits1, splits2):
    if split1.num_shards != split2.num_shards:
      return False
  return True