Implement Metrics instrumentation

[Xunzhuo]

Description:

Do metrics instrumentation in EG components:

• [x] Provider:
  • [x] controller-runtime metrics
  • [x] watchable map metrics
• [x] GWAPI-Translator
  • [x] watchable map metrics
• [x] xDS-Translator
  • [x] watchable map metrics
• [x] xDS-Server
  • [x] watchable map metrics
  • [x] xds server metrics
• [x] Infra-Manager
  • [x] watchable map metrics
  • [ ] infra-manager metrics
• [x] Status Updater

Implement Metrics instrumentation for EG CP Observability.

• [x] https://github.com/envoyproxy/gateway/issues/2089
• [x] https://github.com/envoyproxy/gateway/issues/2090
• [ ] https://github.com/envoyproxy/gateway/issues/2091
• [x] https://github.com/envoyproxy/gateway/issues/2131
• [ ] #3474

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had activity in the last 30 days.

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had activity in the last 30 days.

[arkodg]

@Xunzhuo still planning on working on this for v1.0 ?

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had activity in the last 30 days.

[shawnh2]

The design of Metrics for EG CP shall follow the idea as @Xunzhuo outlined here.

I'll post the initial metrics design here (one by one) before any implementation.

[Xunzhuo]

@shawnh2 thanks for continuing to implement this, ping me if you need more reviews.