修复：表格右上角自定义列与自定义列排序

[coolhihi]

Fix sort and toggle in tableSetting.

Types of changes

• New feature
• Bug fix
• Documentation change
• Coding style change
• Refactoring
• Performance improvement
• Test cases
• Continuous integration
• Typescript definition change
• Breaking change

Background and context

list/search-table/index.vue
该示例表格右上角提供自选显示列和自定义列排序，但有缺憾：
1、当取消多个勾时实际只取消最后一个，重新勾上会导致出现重复列。
2、排序算法与drag的页面效果不符，页面显示效果是其他字段前移或后移，但代码结果是前后位置的两个列直接交换。

Solution

1、使用showColumns作为母本直接重新生成列配置
2、使用splice方式把旧下标的元素插入新下标前，取代原来交换的方式

How is the change tested?

本地dev测试

Changelog

Changelog(CN)	Changelog(EN)	Related issues
修复示例表格search-table右上角提供的自选显示列和自定义列排序	fixed problem about sort and toggle column in search-table page.

Checklist:

• Provide changelog for relevant changes (e.g. bug fixes and new features) if applicable.
• Changes are submitted to the appropriate branch (e.g. features should be submitted to feature branch and others should be submitted to master branch)

Other information