[Lifter] add tests for changes of #353 (ComplexTypes, etc)

[blattm]

The PR #353 contained hotfixes and was therefore merged without adding thorough tests. New tests should be added to cover:

• changes to ComplexTypeMap
• The new UniqueNameProvider class
• Changes to Enum, Struct, Union
• The new Class class
• correct handling of OperationType.member_access

[blattm]

/cib

[github-actions[bot]]

Branch issue-356-_Lifter_add_tests_for_changesof#353_ComplexTypes_etc created!