Add Ref<T> binding support.

[Faless]

Added PtrToArg and GetTypeInfo adapted from Godot.

Also adds a test for it.

Note: Returning references from godot-cpp seem to always require an extra referencing. My guess it that when returning it to godot it gets passed as an object, and that Godot does not create it's internal Ref in time. The instance seem to be destroyed when expected with the extra reference() before return.

Fixes #628 .

[akien-mga]

Thanks!

[akien-mga]

Note: Returning references from godot-cpp seem to always require an extra referencing. My guess it that when returning it to godot it gets passed as an object, and that Godot does not create it's internal Ref in time. The instance seem to be destroyed when expected with the extra reference() before return.

I suggest opening an issue to keep track of it.

Might also be relevant: godotengine/godot#53135