Is it possible to implement a scalar that returns a result from its to_output method?
In the end it should look something like this:
#[derive( GraphQLScalar)]
#[graphql(
    name = "Scalar",
    to_output_with = Self::to_output,
    from_input_with = Self::from_input,
   )]
pub struct Scalar(bool);
impl Scalar {
    fn to_output(value: &Scalar) -> Result<String, Err> { ... }
    fn from_input(input: &str) -> Result<Self, Err> { ... }
}