FEATURE: 布局选择双列（混合双列、双列），一级菜单宽度支持调整

[wyc001122]

Version

Vben Admin V5

Description

双列布局下，一级菜单名称过长有点遮挡

Proposed Solution

希望通过调整 preferences.sidebar.mixedWidth 修改宽度。

以及似乎还有一些配置例如 preferences.footer.height preferences.header.height preferences.sidebar.extraCollapsedWidth 等 VbenAdminLayout 组件没有接收

Alternatives Considered

No response

Additional Context

No response

Validations

• [x] Read the docs
• [x] Ensure the code is up to date. (Some issues have been fixed in the latest version)
• [x] I have searched the existing issues and checked that my issue does not duplicate any existing issues.