Templating: Link label to input (#85329)

Pass id to VariableInput

public/app/features/variables/pickers/shared/VariableInput.tsx

@@ -34,6 +34,7 @@ export class VariableInput extends PureComponent<Props> {
             instance.setAttribute('style', `width:${Math.max(instance.width, 150)}px`);
           }
         }}
+        id={id}
         type="text"
         className="gf-form-input"
         value={value ?? ''}