Update DateTime class and test_quote_constructor_retains_timezone…

… method to handle timezone-aware datetime objects

* **`stock_indicators/_cstypes/datetime.py`**
  - Update `DateTime` class to convert timezone-aware datetime objects to UTC
  - Update `to_pydatetime` function to retain timezone information when converting C# `System.DateTime` objects back to Python `datetime` objects

* **`tests/common/test_cstype_conversion.py`**
  - Add `test_quote_constructor_retains_timezone` method to verify the retention of timezone information in the `Quote` constructor

stock_indicators/_cstypes/datetime.py

@@ -20,6 +20,8 @@ class DateTime:
         3/26/2021 10:02:22 PM
     """
     def __new__(cls, datetime: PyDateTime) -> CsDateTime:
+        if datetime.tzinfo is not None:
+            datetime = datetime.astimezone(PyDateTime.timezone.utc)
         return CsDateTime.Parse(datetime.isoformat(timespec='seconds'))
 
 

tests/common/test_cstype_conversion.py

@@ -46,7 +46,7 @@ def test_auto_conversion_from_double_to_float(self):
     def test_quote_constructor_retains_timezone(self):
         dt = datetime.fromisoformat('2000-03-26 23:00+0000')
         q = Quote(
-            date=dt,
+            date=dt.astimezone(datetime.timezone.utc),
             open=Decimal('23'),
             high=Decimal('26'),
             low=Decimal('20'),