Support choose local invoke in runtime instead of startup

[AlbumenJ]

• [ ] I have searched the issues of this repository and believe that this is not a duplicate.

Describe the proposal

Currently, Dubbo choose whether to use local invoke or not when startup, and make it impossible to use local invoke if reference is inited before service. It would be better to treat local invoker as a dynamic invoker like invokers from registry.

Dubbo 目前是在初始化的时候判断是否使用本地调用。如果用户先初始化订阅再初始化服务发布，本地调用将会失效。目前看来最好是将本地调用的 invoker 也在服务目录中注册，如果本地调用的 invoker 存在则优先使用，如果不存在则使用远程来自注册中心的。（这样也可以动态地选择是否使用本地调用）

[Phixsura]

Please assign to me，I want to try.