Examples: Add textured assets to webgl_loader_fbx(cleanup fbx).

[tatsuya-ogawa]

Related issue: #31067 (comment)

Description

• cleanup monkey fbx model
• I checked texture memory with following code, and texture does not increased.

gui.add( params, 'asset', assets ).onChange( function ( value ) {
    console.log( renderer.info.memory );
   loadAsset( value );
} );