Banner impression data provided by the WMF needs to be stored in a database for use by the a/b test analysis tool. There are some additional steps during processing the numbers to meet the requirements of the a/b test analysis tool.
**Acceptance Criteria**
* In the analytics and reporting tools of the Fundraising operation center, the new values are being used and displayed.
* There is a way to switch data sources for the numbers.
**Notes**
It might be a good idea to keep both setups in parallel for the upcoming campaign. We'd need different application entry points, data tables and a simple way to switch data sources for a/b test analysis during the campaign.
Changing this touches parts of the application that would be happy about refactoring.
**Implementation hints**
* Extract and break down `Analysis::getImpressions()` into smaller classes/methods.