Test retrieving Radios elements using GraphQL 4.

Closes #3426650

tests/queries/radios.gql

 fragment webformElementOption on WebformElementOption {
   __typename
   title
+  description
   value
 }
 
 fragment webformElementRadios on WebformElementRadios {
   __typename
-  id
-  title
-  description
+  type
+  metadata {
+    key
+    type
+    title
+    description
+    required
+    requiredError
+  }
   options {
     ...webformElementOption
   }
 }
 
-fragment webformElement on WebformElement {
-  ...webformElementRadios
-}
-
 fragment webform on Webform {
   title
   elements {
-    ...webformElement
+    ...webformElementRadios
   }
 }