Support SourceMap for transformation

[ChasLui]

No description provided.

[antfu]

I don't use source map myself so this is kinda a low priority to me. While this should not be hard using magic-string, open for contributions if anyone really need that. Thanks

[raphaelsaunier]

Thanks so much for fixing this regardless! @antfu 🙏

Not a heavy user of soucemaps either, but it feels good to no longer see a wall of with a 100+ Sourcemap is likely to be incorrect: a plugin (vite-plugin-components) was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help warnings when building an app.