GLTFExporter: prevent exporting ShaderMaterial

Consider the case when vrdisplaypresentchange fires but device is null.

Fix #11962 Remove WebGLUtils and renderer dependency

Examples: Added Sobel Edge Detection

GLTF2Loader: Rename to GLTFLoader.

fix DragControl not work on mobile

Check asset existence to detect glTF version

GLTF2Exporter: Allow single object and list of objects instead of just scenes

Re-add "accessors" as mesh dependency

Needed for `addMorphTargets`, which accesses `accessors` on `dependencies`

Include GLTF2 exporter in examples

WWOBJloader2 only applying first texture

GLTF2 Exporter

GLTF2Loader: Top-down loading for textures, buffers, and bufferviews.