feat: add ability to publish metrics as ceramic model instance documents (rebased)

[gvelez17]

Description

This PR enables publishing metrics to the ceramic network as model instance documents. It uses the same count and observe semantics as ServiceMetrics, with a configurable interval for publishing.

Key Design notes

• avoids circular dependencies. the observability model-metrics package accepts a ceramic api instance at run time, so never imports any js-ceramic common packages.

• singleton pattern. because of the instance import and that its instantiated as a singleton, you can import model-metrics from a code path where the ceramic instance is not accessible, and still use it; also no need to pass it around, just import

• lightweight functions. the count observe and recordError functions are very lightweight, and only update variables in memory. At the configured interval time, a summary will be published as a model metric.

These designs are in the model-metrics package in the observability repo which is a dependency of this PR. The code is separate from js-ceramic but the npm package is published under @ceramicnetwork/model-metrics

How Has This Been Tested?

Describe the tests that you ran to verify your changes. Provide instructions for reproduction.

• [x ] Tested manually with a local node on dev-unstable, verified that metrics are correctly produced.

To reproduce this test, add the following into daemon.config.json and run your node.

"metrics": {
    "metrics-publisher-enabled": true
  }

• [ x] Tested Manually with a harness at https://github.com/3box/runbooks-and-oncall/tree/main/MetricsDemo (see readme for instructions)

PR checklist

Before submitting this PR, please make sure:

• [x] I have tagged the relevant reviewers and interested parties
• [ ] I have updated the READMEs of affected packages
• [ ] I have made corresponding changes to the documentation

References:

Please list relevant documentation (e.g. tech specs, articles, related work etc.) relevant to this change, and note if the documentation has been updated.