[spike] Create Generic Communication Harness

(Please see the related issue for the full outline of the proposed solution.)

• Objections to this approach?
  • None raised during 2021-11-03 (or preceding) Working Group meetings
• Identify well-contained area to work with to implement a first draft
  • Good candidates will have:
    1. Few destinations (e.g. only Sentry, or only Snowplow)
    2. Minimal integrations (e.g. only one or two implementations - like tracking one button click in Snowplow)
    3. Frontend logic in JavaScript (there's no expectation of building this with hooks into HAML)
  • Good candidates might have:
    1. Already centralized their integration(s) into a single location
    2. Non-trivial use of "Event Hub"-type communication
    3. Lighter current workloads that could allow for some time to debug potential integration issues
       • It's not expected that there will be serious issues, of course, but a team that can handle potential problems without significantly impacting their deliverables will likely feel less stress about this trial.
• Draft and deploy first pass of Communication Harness
  • Base implementation
  • Adapter extensions
  • grouppipeline authoring integration
• Work with team to refine draft into "beta" or RFC candidate.