Returns a list of all avilable templates in environment.

        This considers the loaders on the :attr:`app` and blueprints.

def list_templates(self) -> List[str]:
        """Returns a list of all avilable templates in environment.

        This considers the loaders on the :attr:`app` and blueprints.
        """
        result = set()
        for loader in self._loaders():
            for template in loader.list_templates():
                result.add(str(template))
        return list(result)