input: Write a function to store and query user data using JSON files. User data is provided as a dictionary and should be stored in a JSON file named 'user_data.json'. The function should also allow querying the user data from the JSON file and returning it as a dictionary. If the file does not exist or is empty, the function should return None.
  assert store_user_data({"Name": "John", "Age": 25, "City": "New York"}) == None
  assert get_user_data() == {"Name": "John", "Age": 25, "City": "New York"}
  assert store_user_data({"Name": "Kate", "Age": 30, "City": "Los Angeles"}) == None
  assert get_user_data() == {"Name": "Kate", "Age": 30, "City": "Los Angeles"}
  assert store_user_data({}) == None
  assert get_user_data() == None
output: def store_user_data(user_data):
      with open('user_data.json', 'w') as file:
          json.dump(user_data, file)
      return None
  
  def get_user_data():
      try:
          with open('user_data.json', 'r') as file:
              data = json.load(file)
              if data:
                  return data
              else:
                  return None
      except (FileNotFoundError, json.JSONDecodeError):
          return None