Rename "Add Node Here to Add 2D Node Here to avoid confusion when right click on 2d scene to add nodes

[jsjtxietian]

As @AThousandShips suggested in #91512 (comment)

[timothyqiu]

This makes things clearer technically. But I don't think users who would try to instantiate AnimationPlayer in a 2D editor would understand what a Canvas Node is.

I would suggest changing it to simply "Add Node", not restricting to CanvasItem only, and move the newly created node if it's 2D / Control.

[KoBeWi]

That option originally allowed adding any node, but was changed on request: #41437 (comment)
If it's confusing, maybe it can say "Add 2D Node Here".

[Mickeon]

In my opinion it we really want to mention "canvas nodes" it should be the full name of the class ("Add CanvasNode Here...") to keep it untranslated.

But "Add 2D Node Here..." is completely fine and more accessible.