Remove node_hrcr hack

[KoBeWi]

Fixes #17573
EDIT: Fixes #54177

node_hrcr was a hack used to force legible_unique_name globally in the editor. This resulted in internal nodes having different name in editor than in game, which is unexpected (see the closed issue).

I removed this hack and instead the editor will now explicitly use the legible_unique_name argument wherever necessary. (I might've missed some places though)

[reduz]

I think this is a very good idea and it may really improve the editor start up performance. I don't think the places where this was manually replaced are enough, though.

From the top of my head, 3D importers (GLTF2, DAE and FBX) need to be checked because it is common that nodes can come without names there (GLTF2 is tricky because it can be used in run-time too, where this check would be unnecessary, but it would still be for importing), and I am unsure whether I am missing something else. This would be good to have other contributors involved to make 100% sure we are not forgetting anything.

If you nag me over the week, I can give a general check of places where add_child is used to give you better feedback.

[KoBeWi]

@reduz I went over all usage of add_child in the codebase and hopefully I didn't miss anything (but I might've changed some unnecessary extras).

[akien-mga]

Seems good to me, I'll let @reduz have a quick look at the changed add_childs to confirm.

[akien-mga]

Let's merge and see if we spot anything unexpected.

[akien-mga]

Thanks!