feat: 增加extra

Author: Roxannej

src/Dialog/Content/index.tsx

@@ -37,6 +37,12 @@ const Content = React.forwardRef<ContentRef, ContentProps>((props, ref) => {
 
   const panelRef = useRef<PanelRef>(null);
 
+  const hasExtra =
+    extra !== null &&
+    extra !== undefined &&
+    typeof extra !== 'boolean' &&
+    !(typeof extra === 'string' && extra.trim() === '');
+
   // ============================== Refs ==============================
   React.useImperativeHandle(ref, () => ({
     ...panelRef.current,