Append client version info to graffiti

[chong-he]

Issue Addressed

• Allow appending/prepending graffiti to client version info #7201

Additional Info

Thank you @ethDreamer and @michaelsproul for the help and guidance

[ethDreamer]

This is the wrong place to do this. This function will call produce_block_with_verification() which will call produce_block_on_state() which will call the graffiti_calculator.get_graffiti() again. I would suggest you pass this argument down the function calls along with the graffiti. So maybe (inside graffiti_calculator.rs) create some new enum:

enum GraffitiSettings {
    Unspecified,
    Specified {
        graffiti: Graffiti,
        policy: GraffitiPolicy,
    }
}

impl GraffitiSettings {
    fn new(validator_graffiti: Option<Graffiti>, policy: GraffitiPolicy) {
        validator_graffiti.map(|graffiti| Self::Specified {
            graffiti,
            policy,
        })
        .unwrap_or(Self::Unspecified)
    }
}

and pass that down through the functions. Then you'd want to change get_graffiti to:

pub async fn get_graffiti(&self, graffiti_settings: GraffitiSettings) -> Graffiti

[chong-he]

Thanks so much for the comment, made some amendment based on your comment. If you have some time to spare, will appreciate for another look to see if this is on the right track @ethDreamer