Refactor the filter to_yaml_string used in YAQL/Jinja expressions to be able to handle mongodb base types such as BaseDict and BaseList. The filter will call a helper function to recursively convert BaseDict and BaseList to python dict and list respectively.

Use if-elif instead of multiple if statements to check types when converting from MongoDB BaseDict and BaseList to python dict and list types. Once the value is converted, use another if-elif block to recursively evaluate and convert the values of dict and list.