[Feature] Custom Serializer For OptionsChainsData For Outputting List Of Records (#7035)

* add a custom serializer to OptionsChainsData to convert model output to list of dictionaries

* unused items

---------

Co-authored-by: Theodore Aptekarev <aptekarev@gmail.com>

openbb_platform/core/openbb_core/provider/standard_models/options_chains.py

@@ -12,7 +12,7 @@ from openbb_core.provider.utils.descriptions import (
     QUERY_DESCRIPTIONS,
 )
 from openbb_core.provider.utils.options_chains_properties import OptionsChainsProperties
-from pydantic import Field, field_validator
+from pydantic import Field, field_validator, model_serializer
 
 
 class OptionsChainsQueryParams(QueryParams):
@@ -351,3 +351,22 @@ class OptionsChainsData(OptionsChainsProperties):
         if isinstance(v[0], str):
             return [datetime.strptime(d, "%Y-%m-%d") if d else None for d in v]
         return v
+
+    @model_serializer
+    def model_serialize(self):
+        """Return the serialized data."""
+        data: dict = {}
+        for field in self.model_fields:
+            value = getattr(self, field)
+            if isinstance(value, list):
+                if value:  # Check if the list is not empty
+                    if isinstance(value[0], datetime):
+                        data[field] = [str(v) if v else None for v in value]
+                    else:
+                        data[field] = value
+            else:
+                data[field] = value
+
+        records = [dict(zip(data.keys(), values)) for values in zip(*data.values())]
+
+        return records