Cannot Access/Modify Debug Arrow of one-way CollisionShape2Ds

### Tested versions

- Reproducible in v4.3.stable.official [77dcf97d8]
- Reproducible in v4.2.stable.official [46dc27791]

### System information

Godot v4.3.stable - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060 Ti (NVIDIA; 31.0.15.3758) - AMD Ryzen 5 1600 Six-Core Processor (12 Threads)

### Issue description


_Visual Description of Image: A blank Godot project with a single StaticBody2D node. It has a single child, a CollisionShape2D. Because the collision shape has the one-way property set to true, the screenshot shows an arrow underneath it. This arrow is highly distorted as a result of the scaling performed on the CollisionShape2D node and the relative size of the RectangleShape2D node._

**Issue description**: Visually, the editor is working as intended. The issue is that I'm making a tool based on StaticBody2D, and I cannot access the arrow polygon or modify it.

This could potentially be considered a feature proposal. But there is a chance that the arrow is not supposed to be drawn this large in any circumstance, so I'm submitting this as a general issue.

### Steps to reproduce

You can use the MRP to see this outcome, but here are the steps to reproduce:

1. Create StaticBody2D and child CollisionShape2D with RectangleShape2D for example
2. In StaticBody2D, enable one-way collision.
3. In CollisionShape2D, specify the scale to ( 300, 20 )
4. In RectangleShape2D, specify the size to ( 1, 1 )

### Minimal reproduction project (MRP)

[MRP.zip](https://github.com/user-attachments/files/17171980/MRP.zip)

Start by reproducing the one-way CollisionShape2D setup from the listed steps or the attached MRP, then trace the Godot editor code that draws the debug arrow for one-way collision. Determine whether the arrow should be scaled differently or exposed for tool-based modification; done means the reported distorted arrow behavior is addressed and the result is covered by an appropriate editor check.

Written by the indexing model from the issue text.