Fix 'quick fix add attribute/function/class' for dynamic interfaces

(Also includes fixes for regular interfaces)

With this fix
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For any type of interface (regular or dynamic) :
* quick fix 'add attribute/function/class' add **formal** attribute/function/class (instead of concrete before)
* quick fix 'add object' **deactivated**

FTR Without this fix
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For any type of interface (regular or dynamic) :
* add attribute was concrete : broken for regular and dynamic interfaces
* add function was concrete : broken for dynamic interface
* add class was concrete : broken for dynamic interface
* add object was activated : broken for regular and dynamic interfaces