Refactor: Split HasValidate implementations for four different extractors into multiple files and export them using feature flags

src/form.rs

@@ -0,0 +1,21 @@
+//! # Implementation of the `HasValidate` trait for the `Form` extractor.
+//!
+
+use crate::{HasValidate, ValidRejection};
+use axum::extract::rejection::FormRejection;
+use axum::Form;
+use validator::Validate;
+
+impl<T: Validate> HasValidate for Form<T> {
+    type Validate = T;
+    type Rejection = FormRejection;
+    fn get_validate(&self) -> &T {
+        &self.0
+    }
+}
+
+impl From<FormRejection> for ValidRejection<FormRejection> {
+    fn from(value: FormRejection) -> Self {
+        Self::Inner(value)
+    }
+}