[xlings | PR]: 优化非xlings工具安装软件的检测, 并修复windows下系统中已安装vscode后重复安装的问题

[SPeak]

• issues详情: https://github.com/d2learn/xlings/issues/104
• pr详情: https://github.com/d2learn/xlings/pull/105

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修复代码&测试结果

验证步骤

1.更新xlings到最新版本

irm https://d2learn.org/xlings-install.ps1.txt | iex

2.更新包索引

xim --update index

3.测试

xlings remove code
xlings self clean
xlings install code

预期输出

code@system - already installed