Let get_class() return Variant instead of String

[MaaaxiKing]

Describe the project you are working on

Reaction game

Describe the problem or limitation you are having in your project

I cannot get a class itself, I get the name of the class as type String and so cannot use is. I try to do if child is _class.get_class(): but the right operand of is is not of type class, it is a String.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

One could use the is keyword for that.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

Variant get_class() const
If one would really need the String of the class, one could just do str(<Object.>get_class()).

If this enhancement will not be used often, can it be worked around with a few lines of script?

No.

Is there a reason why this should be core and not an add-on in the asset library?

Yes, it is very useful.

[Calinou]

Duplicate of #391.