feat(admin): 新增搜索表单多选功能 add xmSelect plugin support for multiple selection

- Add xmSelect case handling in AdminController for 'in' operation
- Include xmSelect.js in admin layout
- Update easy-admin.js to support xmSelect initialization and data binding
- Modify goods.js to demonstrate xmSelect usage with simulated data
- Adjust public.css for better styling of xmSelect elements

Signed-off-by: wolfcode <37436228+wolf-leo@users.noreply.github.com>

app/admin/view/layout/default.html

@@ -26,6 +26,7 @@
             EDITOR_TYPE: "{$adminEditor|default='wangEditor'}",
         };
     </script>
+    <script src="/static/plugs/xmSelect/xm-select.js" charset="utf-8"></script>
     <script src="/static/plugs/layui-v2.x/layui.js" charset="utf-8"></script>
     <script src="/static/plugs/require-2.3.6/require.js" charset="utf-8"></script>
     <script src="/static/config-admin.js?v={$version}" charset="utf-8"></script>