Refactor query caching tests

[morozov]

Q	A
Type	improvement
BC Break	no

The primary goal of this patch is to get rid of the dependency of the test suite on the DebugStack class which will be later deprecated in #4967.

Additionally, the current CachedQueryTest has the following issues:

1. There isn't much point in testing a caching layer via functional tests. The caching layer by its nature shouldn't affect the functionality of the component that it wraps. Only the interaction between the components needs to be tested.
2. Most of the tests cover fetching data from the cache in different modes and their combinations. Those tests are irrelevant as of Always cache the full result #5003.
3. Testing different cache implementations makes sense but testing that replacing a cache implementation invalidates the cache is enough to be tested just with the default implementation because this logic doesn't depend on the implementation.