[Feature Request] Improve service_entry.get

[michaeldcanady]

Example code:

def get(self, key: str, _type: Optional[Type[R]] = None) -> Union[R, datetime, str, None]:
        
        if _type is None:
            _type = ServiceNowEntry
        
        raw_value = self[key]
        if isinstance(raw_value, ServiceNowProperty):
           if _type == datetime:
              return self.parse_servicenow_datetime(raw_value.actual_value)
           return self._get_value(raw_value, _type)
         if issubclass(_type, ServiceNowPropertyCollection):
            return _type(self.Client).import_servicenow_property_collection(raw_value)
        raise ValueError(f"value: {raw_value} of type: {type(raw_value)} is unexpected")