Bring back validator error extensions

[cortopy]

Description of the feature

I've been digging into past versions and it seems that there used to be trait called InputValueValidator that allowed to return an Error with extensions after this PR #564

This solved this request #385, which is exactly what I'm trying to achieve.

Without Error extensions, it's difficult for frontend clients to know what exactly is wrong, but the current trait of CustomValidator only allows to return a String in the check method.

Could the old behaviour be brought back? I don't see any removal notes from the CHANGELOG either

[sunli829]

Fixed in master, here is the example:

async-graphql/tests/validators.rs

Line 582 in c54591d

InputValueError::custom(format!("expect 100, actual {}", value))

[sunli829]

Released in v5.0.4

[cortopy]

Thanks so much @sunli829 for being this quick!!!

I've tested the new version and it's great but I still can't use custom Graphql errors.

For example:

#[derive(Debug, Error)]
pub enum GraphqlError {
    #[error("InternalServerError")]
    InternalServerError(String),
    #[error("Could not find resource")]
    NotFound,
    #[error("Unauthenticated")]
    Unauthenticated,
    #[error("Invalid user input")]
    BadUserInput(HashMap<String, String>),
}

impl ErrorExtensions for GraphqlError {
    fn extend(&self) -> FieldError {
      ...
    }
}

I can't do this:

let fields = HashMap::new();
let error: InputValueError = GraphqlError::BadUserInput(fields).extend().into()

because async_graphql::Error doesn't implement std::fmt::Display