Fix more Python 3.10+ union type parsing issues

[Callum027]

• Fix parsing Python 3.10+ type hints when encoding search filters.
• Fix parsing Python 3.10+ type hints when decoding record values.
• Add missing release note for fixing parsing Python 3.10+ type hints when evaluating model refs.

[Callum027]

Appears to be a bug caused by this.

  File "...", line 382, in _add_term_discounts
    project_term_discounts = self.odoo_client.term_discounts.search(
                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../openstack_odooclient/base/record_manager/base.py", line 548, in search
    ids: list[int] = self._env.search(
                     ^^^^^^^^^^^^^^^^^
  File ".../odoorpc/models.py", line 59, in rpc_method
    result = cls._odoo.execute_kw(cls._name, method, args, kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../odoorpc/odoo.py", line 524, in execute_kw
    data = self.json(
           ^^^^^^^^^^
  File ".../odoorpc/odoo.py", line 271, in json
    data = self._connector.proxy_json(url, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../odoorpc/rpc/jsonrpclib.py", line 110, in __call__
    data_json = json.dumps(data)
                ^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/json/encoder.py", line 200, in encode
    chunks = self.iterencode(o, _one_shot=True)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/json/encoder.py", line 258, in iterencode
    return _iterencode(o, 0)
           ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/json/encoder.py", line 180, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type date is not JSON serializable

EDIT: This is happening because type_hint_origin is being used here instead of type_hint.

python-openstack-odooclient/openstack_odooclient/base/record_manager.py

Line 968 in 34f1999

else type_hint_origin

This bug has existed since the start, but recent changes in clients have caused this particular code path to be used for a date | None type attribute. Will fix as part of this PR.

EDIT 2: Fix tested and commited.

>>> encode_value(list[datetime], [datetime.now()])
['2025-12-15 14:29:46']
>>> encode_value(list[Union[datetime, date]], [datetime.now(), date.today()])
['2025-12-15 14:30:01', '2025-12-15']
>>> encode_value(int, 123)
123
>>> encode_value(float, 123)
123
>>> encode_value(date, datetime.today())
'2025-12-15'
>>> encode_value(date, date.today())
'2025-12-15'
>>> encode_value(datetime, datetime.now())
'2025-12-15 14:31:05'
>>> encode_value(datetime | None, datetime.now())
'2025-12-15 14:31:14'
>>> encode_value(Union[datetime, None], datetime.now())
'2025-12-15 14:31:25'
>>> encode_value(datetime | None, None)
>>> encode_value(Union[datetime, None], None)
>>> encode_value(Optional[datetime], datetime.now())
'2025-12-15 14:32:08'
>>> encode_value(Optional[datetime], None)
>>> encode_value(list[datetime], [datetime.now()])
['2025-12-15 14:32:23']
>>> encode_value(list[Union[datetime, date]], [datetime.now(), date.today()])
['2025-12-15 14:32:27', '2025-12-15']