dispose method

Implementation

void dispose([List<FlutterAngleTexture?>? textures]) {
  textures?.forEach((t) {
    if(t!=null)deleteTexture(t);
    t = null;
  });
  textures?.clear();
  if(_baseAppContext != nullptr && !Platform.isLinux){
    _libEGL!.eglDestroyContext(_display, _baseAppContext);
    _baseAppContext = nullptr;
  }

  _worker?.dispose();
  _worker = null;
  _libOpenGLES = null;
  _libEGL!.dispose();
  _disposed = true;
}