Rename Node3D's property translation to position

[madmiraal]

Currently, Node3D has a helper property called translation, which would be better called position as exists in Node2D. This PR renames Node3D's translation property, position.
Part of #16863.

Bugsquad edit: Fixes godotengine/godot-proposals#1557

[aaronfranke]

I support this change and the code looks good. Would also be nice to update the docs for Node2D.position to match though.

[bluenote10]

See my concerns in the proposal godotengine/godot-proposals#1557.

[madmiraal]

Rebased following merge of #45879.

[madmiraal]

Updated documentation with --doctool ..

[akien-mga]

We discussed this in a PR preview meeting today, and it had been discussed on and off in chat in previous months too. With the contributors present, we finally reached a consensus that this rename might indeed be a good idea to make things consistent.

translation is more "accurate" for experienced 3D developers, but Godot aims at being user-friendly also to less savvy developers, and position is still a correct description of what this represents. So we prefer standardizing on position for both 2D and 3D than the other way around, assuming that translation in 2D would confuse beginners even more. Other issues with translation is the homonymy with text/language translation (localization), and the similarity with transform which also starts with trans-.

[akien-mga]

Good to merge after a rebase.

[akien-mga]

Thanks!

[aaronfranke]

@Calinou Surprisingly I don't actually think this is a problem. Exactly zero of the scenes in the demo projects have translation = in them, because 3D nodes currently store a Transform3D for their transformations. The only cases where translation exists in the scene files is with animation tracks that animate the translation property.

[Calinou]

@Calinou Surprisingly I don't actually think this is a problem. Exactly zero of the scenes in the demo projects have translation = in them, because 3D nodes currently store a Transform3D for their transformations. The only cases where translation exists in the scene files is with animation tracks that animate the translation property.

Indeed, I was mistaken as only transform is saved in scene files for nodes. I removed my earlier comment due to this.