✨ Refactor ResponseHelper and add ResponderHandler

- Modified ResponseHelper.Body signature to return an io.Reader and an error.
- Updated ResponseHandler.ServeHTTP to handle errors from ResponseHelper.Body.
- Implemented JSONResponse and JSONResponseWithStatus functions for easier JSON responses.
- Added comprehensive unit tests for JSON response handling, including error scenarios.
- Extended Helper.ResponderHandler with a new test case to ensure proper error handling and response generation.
- Resolved linting issues related to dynamic error definition and function length in tests.

helper.go

@@ -34,3 +34,9 @@ func (help *Helper) HandlerFunc(hnd HandlerFunc) http.Handler {
 		}
 	})
 }
+
+// ResponderHandler returns an [http.Handler] for the provided [ResponderHandler].
+// If hnd returns an error, an appropriate error response is written using the ErrorHandler.
+func (help *Helper) ResponderHandler(hnd ResponseHandler) http.Handler {
+	return help.Handler(hnd)
+}