Migrate compatibility samples

[zbchi]

migrate existing samples under compatibility/ to the new standard sample layout, without changing their original functionality

[AlexStocks]

dubbogo v3.3.1 已经发布，现在剩下的例子，还有哪些是可以删掉，那些是可以升级的，能否给个列表出来？

[zbchi]

重复删除：
compatibility/task/shop/
compatibility/rpc
compatibility/polaris/limit/
compatibility/config-api/
compatibility/proxyless/

需要迁移：
compatibility/polaris/registry/ → registry/polaris/
compatibility/polaris/router/ → router/polaris/
compatibility/mesh/ → mesh/
compatibility/apisix/ → apisix/

推迟删除：
compatibility/generic