Fix TruncationDirection with serde alias instead

With `#[serde(alias = "...", ...)]` we wouldn't break anything
user-wise, whilst allowing for both "left"/"Left" and "right"/"Right" to
be provided as `truncation_direction` other than only the capitalized
version of those

Author: alvarobartt

router/src/http/types.rs

@@ -194,9 +194,10 @@ impl<'__s> ToSchema<'__s> for PredictInput {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Deserialize, ToSchema, Eq, Default)]
-#[serde(rename_all = "lowercase")]
 pub(crate) enum TruncationDirection {
+    #[serde(alias = "left", alias = "Left")]
     Left,
+    #[serde(alias = "right", alias = "Right")]
     #[default]
     Right,
 }