Release v0.6.0

⭐ Feature

• Support xDS protocol to communicate with the Control Plane of Service Mesh. Issue sermant-io#1515
  (1)Implements communication based on the xDS protocol and Istio data plane.
  (2)Implements the service discovery capability in the K8S scenario based on the CDS and EDS protocols.
  (3)In the Kubernetes scenario, the Sermant framework implements the service discovery capability based on the CDS and EDS protocols and provides an interface for the Sermant plugin to obtain service instances.
• Support configuration management on the sermant-backend. Issue sermant-io#1528
  (1)Support configuration management on the sermant-backend page.
  (2)Support Zookeeper, Nacos, and Kie configuration centers.

📈 Improvements

• Refactor all packages to io.sermant to keep a consistent directory structure. Issue sermant-io#1505
• Reconstruct the dynamic configuration service and provide services for the sermant-backend through a unified interface. Issue sermant-io#1523
• Reduce startup time of sermant-agent. Issue sermant-io#1541
• Support user-defined parameters on the attach command. Issue sermant-io#1552
• Support English version for sermant-backend. Issue sermant-io#1553
• Support the Redis cluster on the sermant-backend. Issue sermant-io#1555

🐞 Fixes

• Fix the issue that the unit test of the springboot-registry plugin fails to be executed. Issue sermant-io#1501
• Fix the issue that the plugin configuration fails to be dynamically loaded for the second time. Issue sermant-io#1520
• Fix the issue that the ConfigSubscriber mode not support Map. Issue sermant-io#1536
• Fix Open-Source Software Vulnerabilities. Issue sermant-io#1558

📔 Documentation

• Translate code comments and documents into English. Issue sermant-io#1466
• Add Licenses for project dependencies. Issue sermant-io#1499