Stats refresh

[danielbachhuber]

Done is:

• New calculation methods are applied across these experiment types:
  • Trend count
  • Trend continuous
  • Funnel
• [x] Separate out trend count methodology from Jupyter notebook @jurajmajerik
• [ ] Separate out trend continuous methodology (property value) from Jupyter notebook @jurajmajerik
• [ ] Separate out funnel methodology from Jupyter notebook @jurajmajerik
• [ ] Verify explanations make sense with SME @jurajmajerik
• [ ] Remove "Count per user" from Trend experiment setup (but shouldn't impact Insights)
• [ ] Apply trend count methodology to ExperimentTrendsQueryRunner
• [ ] Apply trend continuous methodology to ExperimentTrendsQueryRunner
• [ ] Apply funnel methodology to ExperimentFunnelQueryRunner
• [ ] Configure new methodology behind a feature flag in order to evaluate results
• [ ] Enable new methodology for all experiments (based off a bit when the experiment is created)
• [ ] Documentation is written / updated