Freemius revenue attribution and a full reports view

New

• Freemius revenue attribution, with per-product tracking and sale amounts verified on the server.
• Six metrics: unique visitors, visits, page views, revenue, bounce rate and visit duration, plus an exit page report.
• A full reports view with group tabs and row search.
• Settings: track admins, choose first or last click attribution, and opt in to deleting data on uninstall.

Improved

• Error states with retry on every card, and a hardened uninstall.