Invalid use of addType in ChoiceCaseBuilder during copy in yang-parser-impl CopyUtils class

The ChoiceCaseBuilder prohibits adding of TypeDefinitionBuilder via addTypedef method, hence the copy method in CopyUtils in yang-parser-impl project tries to copy typedefs if there are present in ChoiceCaseBuilder which is faulty too.

The wrong implementation is located between lines 136-137 in CopyUtils.java