Simplification property tests: separate Predicate and TermLike generators #2804
Description
Context for this issue: we made the decision that the TermLike simplifier should not call the Predicate simplifier (see #2770). This requires that any TermLike pattern should not contain children patterns which are Predicates. In the future, we would like to fully disentangle the representation of Predicates from TermLikes (see #2640).
Right now, our unit tests we rely on a TermLike generator to generate any type of Kore pattern. This has also lead to sporadic failures of our property tests, as it generates patterns which are too general. We need to implement a separate Predicate generator, and disallow any predicate pattern generation in the TermLike one.