[LiveSync] allow for custom files (extensions) to be handled by liveSync

In my app i need to allow fast live sync for files ".mss"
When those files are changed (in assets), only a reload of the map style is needed.
I already handle that through global.__onLiveSync

But now it does not work anymore. It comes from that line:
https://github.com/NativeScript/nativescript-cli/blob/5069f29fcb0a1dc9abbf3eb5523b298141bb3b11/lib/services/webpack/webpack-compiler-service.ts#L59

I was working a few releases before. If i

Here only files with 'hot-update' will allow live sync. How can i make it work?
Actually how does it work today for images live sync. I can see that it is supposed to be handled seeing fastLivesyncFileExtensions:
https://github.com/NativeScript/nativescript-cli/blob/9320a1de8462e8451f08a4798d35912573f78ac3/lib/services/android-project-service.ts#L85

まず lib/services/webpack/webpack-compiler-service.ts の 59 行目付近を読み、lib/services/android-project-service.ts の 85 行目付近と比較します。特に fastLivesyncFileExtensions に注目してください。画像の変更がどのように liveSync に到達するか、また global.__onLiveSync がどのように関与するかを追跡します。カスタム .mss アセットの変更によって必要な liveSync の動作がトリガーされ、既存の画像処理に影響しなければ完了です。