fix: forward fileType to SplatLoader in PackedSplats.asyncInitialize

[zzha9494]

Fixes #233

Bug: When constructing a SplatMesh with url + fileType, the fileType is never forwarded to the internal SplatLoader instance created in PackedSplats.asyncInitialize(). This causes URLs without recognizable extensions (e.g. Blob URLs) to fail with Unknown splat file type: undefined.

Fix: Add loader.fileType = options.fileType before calling loader.loadAsync(url).

[dmarcos]

Thanks so much. Is this an issue in the 2.0.0 branch: https://github.com/sparkjsdev/spark/tree/v2.0.0-preview ?

[zzha9494]

I tried 2.0.0 branch. This code does not work:
const splats = new SplatMesh({ fileBytes: arrayBuffer, fileType: "sogs", });

However, in 0.1.10, this code works (mesh rendered):
const splats = new SplatMesh({ fileBytes: arrayBuffer, fileType: SplatFileType.PCSOGSZIP, });