fix(macros): reintroduce and fix macro tests for MySQL

sqlx-macros/src/database/mysql.rs

@@ -13,6 +13,7 @@ impl_database_ext! {
         f32,
         f64,
 
+        // ordering is important here as otherwise we might infer strings to be binary
         // CHAR, VAR_CHAR, TEXT
         String,
 

sqlx-macros/src/query/data.rs

@@ -10,6 +10,7 @@ use sqlx_core::executor::Executor;
         deserialize = "Describe<DB>: serde::de::DeserializeOwned"
     ))
 )]
+#[derive(Debug)]
 pub struct QueryData<DB: Database> {
     #[allow(dead_code)]
     pub(super) query: String,