如何修改Splitter分割线的样式？ #52039
Description
Reproduction link
https://ant-design.antgroup.com/components/splitter-cn
Steps to reproduce
无
What is expected?
- Splitter组件左右两侧中间有个分割线，在不禁用resizable的情况下，如何隐藏分割线中间的灰色长方形方框？如下：
- 希望可以增加两个按钮，点击按钮可以将左侧（或右侧）区域折叠或展开
What is actually happening?
无
| Environment | Info |
|---|---|
| antd | 5.22.5 |
| React | lastest |
| System | macos |
| Browser | chrome |