l7-three 支持 mapbox 底图

[lvisei]

实现逻辑：

https://docs.mapbox.com/mapbox-gl-js/example/add-3d-model/

代码修改处：

L7/packages/three/src/core/threeRenderService.ts

Lines 75 to 82 in 78a1e5e

 private mapboxCamera(): Camera { 
   const mercatorMatrix = new Matrix4().fromArray( 
     // @ts-ignore 
     this.mapService.map.transform.customLayerMatrix(), 
   ); 
   this.camera.projectionMatrix = mercatorMatrix.multiply(this.cameraTransform); 
   return this.camera; 
 } 

Originally posted by @lvisei in #2435 (comment)