Framework for more types of contribution credit for organizations

We want to begin expanding the kinds of activities that grant contribution credit - starting with factors that will affect an organization's rank in the marketplace. To start this process we're going to build a generic framework for organization contribution credit, which will be fed by different kinds of contribution types (like the current issue credits), and calculated into a behind the scenes overall contribution score. This initial work is just to build that framework, and experiment with a few new contribution types in a pre-production environment. We'll communicate more as we actually implement new types of credit.

Production outage: No
Change affects: Drupal.org contribution credits/marketplace
Deployment schedule: In development, to be deployed after review with board task force
Backout plan: revert or fix in place