[feature request] Apache Dubbo support in Consul Connect

[Apache Dubbo ](https://dubbo.apache.org/) is a widely used RPC protocol in the microservices ecosystem, which has already been supported by [Envoy proxy](https://www.envoyproxy.io/docs/envoy/latest/configuration/listeners/network_filters/dubbo_proxy_filter).

It would be nice to see Consul Connect to support it in some way. The most important path seems to be a service registration since for Dubbo it's very important to keep the correct meta as Consul tags.