HHH-6747 - ClassCastException when rendering SimpleCaseExpression

Conflicts:
	hibernate-entitymanager/src/main/java/org/hibernate/jpa/criteria/expression/SimpleCaseExpression.java
HHH-4700 - ClassCastException with parameter in
CaseNode.getFirstThenNode() (cherry picked from commit
efa5dc2f6ca1b4f20725e2d58d6afac00dff10b6)

Conflicts:
	hibernate-core/src/main/java/org/hibernate/hql/internal/ast/tree/Case2Node.java
	hibernate-core/src/main/java/org/hibernate/hql/internal/ast/tree/CaseNode.java