Control Items and XRCamera3D

**Your Godot version:**
v4.1.2.stable.official [399c9dc39]

**Issue description:**
I tried to connect a ColorRect to the XRCamera3D because this works for the normal camera. The problem is, it doesn't work and it's not documented anywhere in the official documentation that it doesn't work. I only found out about it through this random issue: https://github.com/godotengine/godot/issues/77060#issuecomment-1547330854

> You cannot use Control nodes in VR, because they are rendered after the 3d scene is drawn. Instead, you should be using a Sprite3D or a Quad mesh positioned in 3D, possibly relative to the XRCamera3D so it's in front of you.

I think the XRCamer3D and the Control documentation should be provided with a warning about this.

**URL to the documentation page (if already existing):**
https://docs.godotengine.org/en/stable/classes/class_xrcamera3d.html#description
https://docs.godotengine.org/en/stable/classes/class_control.html#class-control