Class access modifiers

[NKnusperer]

Is your feature request related to a problem? Please describe the problem.

Currently, all classes generated by Kiota have the public access modifier, which means they are visible to all other projects that reference them. However, the generated SDK code may just be an implementation detail that should not be exposed, so it would be appropriate to have the internal access modifier instead.

Client library/SDK language

Csharp

Describe the solution you'd like

A command line argument for kiota generate that controls the class access modifier, similar to what --class-name already does.

Additional context

No response