支持vscode工作区变量${workspaceFolder}

[HaroldCC]

Is your feature request related to a problem? Please describe.

vscode内置变量${workspaceFolder}获取工作区路径，当有多个工作区时，需要根据路径导出compile_commands.json。 目前xmake-vscode支持${workspaceRoot}，默认路径是打开文件夹的根目录

Describe the solution you'd like

希望与vscode一致，${workspaceFolder}是当前打开文件所在的工作区路径

Describe alternatives you've considered

No response

Additional context

No response

[HaroldCC]

我目前自己实现了一个 #211

[waruqi]

merge 了