[first draft] enhanced version of SqlPredicateTest

Missing features:
- fully configurable customPredicate
- needs more types of customPredicate

Waiting your review.
We could use the `OperationSelector` to configure the used Predicate completely via runtime configuration.

Instead of `PUT, PUT_ASYNC, GET, GET_ASYNC` etc. like in the other tests we could have an enum with the available Predicates (`NAME, AGE, SALARY, ACTIVE`). In the code you prepare all of them and use them depending on the `operationSelector.select()`