chore(FormGroup): simplify bindings between input and form group p… (#704)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

src/runtime/types/form.d.ts

@@ -21,8 +21,8 @@ export interface FormEvent {
 }
 
 export interface InjectedFormGroupValue {
-  labelFor: Ref<string>
+  inputId: Ref<string>
   name: Ref<string>
   size: Ref<string>
   error: Ref<string | boolean>
-}
+}