Use dateutil for parsing datetime strings

[execreate]

Hey there, thanks a lot for the nice tool! I've noticed there is a minor thing with datetime parsing that can be improved. The current implementation throws the following error:

Traceback (most recent call last):
  File "/myproject/venv/lib/python3.10/site-packages/IPython/core/interactiveshell.py", line 3550, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-5-0cf0aa12b443>", line 1, in <module>
    twin = manager.get_twin("my_device")
  File "/myproject/venv/lib/python3.10/site-packages/azure_iot_hub_api/azure_iot_hub.py", line 34, in get_twin
    return Twin.from_dictionary(result)
  File "/myproject/venv/lib/python3.10/site-packages/azure_iot_hub_api/models.py", line 167, in from_dictionary
    status_update_time = datetime.fromisoformat(twin_dictionary.get("statusUpdateTime"))
ValueError: Invalid isoformat string: '2025-01-27T16:35:04.6698773Z'

This pull request should fix this.