feat: cleanup aggregate error for single error

Cargo.lock

@@ -278,7 +278,7 @@ dependencies = [
 
 [[package]]
 name = "notmad"
-version = "0.7.2"
+version = "0.7.3"
 dependencies = [
  "anyhow",
  "async-trait",

crates/mad/src/lib.rs

@@ -49,6 +49,14 @@ impl AggregateError {
 
 impl Display for AggregateError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if self.errors.is_empty() {
+            return Ok(());
+        }
+
+        if self.errors.len() == 1 {
+            return f.write_str(&self.errors.first().unwrap().to_string());
+        }
+
         f.write_str("MadError::AggregateError: (")?;
 
         for error in &self.errors {