CameraAttribute exposure does not consider ambient light, and incorrectly exposes Background

[tele4none]

Tested versions

4.3.stable

System information

Windows 11 - Godot v4.3.stable - Vulkan (Forward+) - dedicated NVIDIA GPU

Issue description

So, there are two problems, both related to the CameraAttribute exposure.

1. Ambient Light Color/Energy does not consider CameraAttribute exposure, Tonemap Exposure works fine.
   There is a related issue, but it is about SDFGI.
   In the picture below, the ambient light color is set to magenta. The first line uses CameraAttribute and the second line uses Tonemap.
   
2. CameraAttribute expose Background "faster" than objects.
   Ambient Light Energy is set to 0 here, and the color of Plane in the scene has been matched with Background to better observe the difference.
   

These two problems make it more difficult to get consistent ambient light from Ambient Light Color when using CameraAttribute for exposure.

Steps to reproduce

1. Create a scene, add WorldEnvironment, directional light and objects.
2. Select any mode in the Environment Background.
3. Select "Color" or "Sky" in Environment Ambient Light Source.
4. Adjust Exposure Multiplier of CameraAttribute and compare with Tonemap Exposure.

Minimal reproduction project (MRP)

exposure-test.zip