[3.3] Introduce `preferred-protocol` for consumer and provider to automatically negotiate the protocol to consume.

[chickenlj]

The following protocol migration document is written based on this feature.

dubbo:
  protocol:
    name: dubbo
    port: 20880
    ext-protocol: tri
    preferred-protocol: tri

https://dubbo-next.staged.apache.org/zh-cn/overview/mannual/java-sdk/reference-manual/upgrades-and-compatibility/migration-triple/

[sonarqubecloud[bot]]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud