Report ConsumeWorkerMetrics on 20ms interval

[apfitzge]

Problem

• 1s interval is too large to report worker metrics
• reporting on a 20s interval, many times per slot, gives us a picture of when and how things are processed as our leader slots progress

Summary of Changes

• Report ConsumerWorkerMetrics on a 20ms interval
• Gives us really great charts like this, showing how quickly we're able to fill blocks:
  

Fixes #

[alessandrod]

backport?

[mergify]

Backports to the beta branch are to be avoided unless absolutely necessary for fixing bugs, security issues, and perf regressions. Changes intended for backport should be structured such that a minimum effective diff can be committed separately from any refactoring, plumbing, cleanup, etc that are not strictly necessary to achieve the goal. Any of the latter should go only into master and ride the normal stabilization schedule. Exceptions include CI/metrics changes, CLI improvements and documentation updates on a case by case basis.