GLTFExporter: Add forcePowerOfTwoTexture option

Decal Example: Geometry => BufferGeometry

Shader Passes: clone defines

Examples: Geometry => BufferGeometry

 Remove the SceneLoader console error log since it's deprecated

SAOPass: cleanup

SAOPass: Fix use of multiple instances

ShadowMaterial: Added .copy()

Remove the SceneLoader console error log

See issue: https://github.com/mrdoob/three.js/issues/13405

GLTFExporter: Add OBJ loader to the scene

GLTFExporter: Texture cache

Clean up GLTFLoader Doc

GLTFExporter: Support metallicRoughnessTexture

Since we don't use MRT there is no need for using the WEBGL_draw_buffers extension.
check https://github.com/mrdoob/three.js/issues/13370

Fix OBJExporter without normals

Fix OBJ loader with empty uvs or normals

GLTFExporter: Added forceIndices for non-indexed geometry

Added THREE.Sky to THREE.Water example