Add support for GLTF Serializer

Currently it is not possible to use the GLTF Serializer functionality due some missing Polyfills. Calling ```GLTF2Export.GLBAsync``` directly is not possible because Native does not have a implementation for Blob. It is simple to modify GLBAsync to export an ```ArrayBufferView``` instead. However, when serializing models with textures we also need ```OffscreenCanvas```. Since this class does not exist in Native we get an exception in the serializer level.