Use a LetPattern

Also reenable printing of LetPattern

simplify terminatingCalls

terminatingCalls now returns calls with integers too.

IntInduction and all integer comparison rules are phased out. Instead
there is a single InequalitySplit rules which splits into (up to) 3 branches,
taking pc into account.

No more EqualitySplit for any other type, except generic types.

Isolate unused rules. Clean up Rules.

Improve QualifiedExamplesBank API

Use Grammars.default
Remove SafeRecursiveCalls

Rules that decompose variables (e.g. ADTSplit) introduce the previous
recomposed expression as a Hint. These Hints are used by the default grammar
when they are of a specific size upwards (currently 4).

More reasonable return type for solveSATWithCores
CEGIS discards tests that crash the evaluator
Try harder to find verifiable solution in validatePrograms
Increase default CEGIS size