How to test the Query Model

[janesser]

The guide demonstrates how easy it is to test aggregates and sagas, i.e. https://docs.axoniq.io/reference-guide/implementing-domain-logic/command-handling/testing and https://docs.axoniq.io/reference-guide/implementing-domain-logic/complex-business-transactions/testing.

It would be great to show ways how to test projections.

There is no evident way to achieve that, despite IntegrationTests starting major portions of the spring-context, especially some entity manager.

Ideally unittesting over projections would be supported.