Load statistics data from server (EXPOSUREAPP-4514) #2115

* Replace mock data with data loaded from server.

* Revert unrelated change.

* Some refactoring, add a generic statistics scope annotation.
Clear retrofit cache on clear.

* Clear statistic data on app reset.

* Unit tests for StatisticsCache.kt

* Implement tests for StatisticsModule init.

* Add tests for statistics api.

* Add statistics server tests that check signature validation behavior.

* Add tests for StatisticsProvider behavior.

* Tests for parsing statistics data.

* LINTING

* Add helper methods to access each cards values, and validate card KeyFigure count and types before exposing them.

* LINTs.

* Rename variable.