[Observability] Add PATH dashboard with OS-level metrics to local development environment.

[adshmh]

Summary

Makes the necessary changes to the Tiltfile to enable adding dashboards.
Adds an OS-level metrics dashboard

Issue

Completes Item 4 of Deliverables from #31:

4. Export, capture and present (in a default dashboard) OS level performance metrics

• [Local Development] Feature parity with poktroll and tilt w.r.t metrics #31

Type of change

Select one or more from the following:

• New feature, functionality or library
• Bug fix
• Code health or cleanup
• Documentation
• Other (specify)

Testing

• All Tests: make test_all
• Documentation: make docusaurus_start; only needed if you make doc changes

Sanity Checklist

• I have tested my changes using the available tooling
• I have commented my code
• I have performed a self-review of my own code; both comments & source code
• I create and reference any new tickets, if applicable
• I have left TODOs throughout the codebase, if applicable