Make lsp backend configurable

[star-hengxing]

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

当用户配置了 lsp 类型为 clangd 时，生成特定的 compile_commands.json

Describe the solution you'd like

加个配置

Describe alternatives you've considered

No response

Additional context

No response

[waruqi]

可以来个 pr

[star-hengxing]

https://github.com/xmake-io/xmake-vscode/pull/245