Expression serialization on subqueries

[nlippke]

It would be great if expression serialization also works on subqueries or CTE-queries. At the moment it looks like that it's not going to work because the serializer expects an incompatible BaseQueryBuilder:

java.lang.ClassCastException: class com.blazebit.persistence.impl.FullSelectCTECriteriaBuilderImpl cannot be cast to class com.blazebit.persistence.BaseQueryBuilder (com.blazebit.persistence.impl.FullSelectCTECriteriaBuilderImpl and com.blazebit.persistence.BaseQueryBuilder are in unnamed module of loader 'app')
	at com.blazebit.expression.declarative.view.ManagedViewTypeCollection.add(ManagedViewTypeCollection.java:62)

if doing something like

cteBuilder = fullCriteraBuilder.fromSubquery(MyCte.class);
ExpressionSerializer<WhereBuilder> serializer = expressionService.createSerializer(WhereBuilder.class);
serializer.serializeTo(serializerContext, predicate, cteBuilder);

[beikov]

This will require to raise the required minimum version of Blaze-Persistence to 1.6.8 after Blazebit/blaze-persistence#1537 is fixed, but should be fine.