Function rerun_what 

pub fn rerun_what(
    corpus_name: String,
    service_name: String,
    severity: String,
    category: String,
    what: String,
    rr: Json<RerunRequestParams>,
    session: Option<AdminSession>,
    pool: &State<DbPool>,
) -> Result<Accepted<String>, Status>

Human rerun — scoped to a severity/category/what.