fix: 修复SplitPane 组件在缺少子元素的时候 size更新失效的问题 修复动画示例对于SplitPane Scroll沉底的问题 重新添加回二级菜单更新跳转

[ai-qing-hai]

• [x] 修复SplitPane 组件在缺少子元素的时候 size更新失效的问题
• [x] 修复动画示例对于SplitPane Scroll沉底的问题
• [x] 重新添加回二级菜单更新跳转

[github-actions[bot]]

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