Remove direct creation of Array and Array2

[grospelliergilles]

There are still parts of code where we directly build instance of Array or Array2:

• [ ] in Array::clone()
• [ ] in Array2::clone()
• [ ] in CaseOptionMultiSimpleT because we derive from ArrayView<Array<T>>.
• [ ] in constructors of Array2 which are public.
• [ ] change the return type of the generated get* functions in axl header.

These methods has to be removed.