[feat] add metrics+health server component for indexer v2 (1/n)

[larryl3u]

Summary

• RFCs: Migrate The Indexer #1258
• Categories: util

• Add simple components for health + metrics server.
  • We use a different approach that drives the processors and there is no metrics component in v2. To support the metrics, we create a component here.

Changelog

• Add health check and metrics endpoint component.

Testing

Locally tested and looks good!

• Metrics

• Health check

Outstanding issues

[musitdev]

My comment is mostly on the fact that if your metric integration is compatible with the Fullnode one.

[larryl3u]

move to #1283 ty!