refactor: add timestamp utility

src/aura_engine/base/utils.py

@@ -34,14 +34,23 @@ class SimpleUtil:
     """
 
     @staticmethod
-    def to_datetime(datetime_str: str):
+    def string_to_datetime(datetime_str: str):
         """
-        Convert a timezone aware date-time string into `datetime`.
+        Convert a ISO 8601 date-time string into `datetime`.
         """
         if datetime_str:
             return datetime.datetime.fromisoformat(datetime_str)
         return None
 
+    @staticmethod
+    def timestamp_to_datetime(timestamp: float):
+        """
+        Convert a timestamp to datetime.
+        """
+        if timestamp:
+            return datetime.datetime.fromtimestamp(timestamp)
+        return None
+
     @staticmethod
     def fmt_time(timestamp: int):
         """