Exclude UI from PostFx by default

[manio143]

Is your feature request related to a problem? Please describe.
It's not expected by users that UI will be rendered with PostFx applied in the default project setup. This comes up often and we direct people to a tutorial on changing it (https://github.com/herocrab/StrideCleanUI https://www.youtube.com/watch?v=cazIR97VPcg)

Describe the solution you'd like
Modify default GraphicsCompositor according to the tutorial and set the default render group in the UI component accordingly.

[Ethereal77]

As UI can be used also in 3D positioned in the scene, it should be excluded from post-FX only if they are marked as fullscreen or something. If not, elements in the scene would be overly bright and incorrect as they avoid tonemapping and other effects the surrounding geometry are affected by.

[VaclavElias]

I am new to Stride, did a bit experimenting with Unity, I am beginner and I agree with @manio143. When we set white colour font for the UI you can't send us to a tutorial and do some ceremony to get the white colour working 🤣.

[Aggror]

I think this can be implemented.

[VaclavElias]

I also want it for code-only approach. There is one already in Stride GraphicsCompositorHelper which I can use and edit before it is used so the white is correct.

var graphicsCompositor = GraphicsCompositorHelper.CreateDefault(true);

// edit graphicsCompositor so the white is white

or I can just create another one and correct the white there
https://github.com/VaclavElias/Stride3DTutorials/blob/main/Other/Minimal/Stride.GameDefaults/GraphicsCompositorBuilder.cs

In my case, it would be good to know how this GraphicsCompositor affects the performance but I can play with that once there is a time for that.

Not sure what needs to be changed in the Stride Studio so the template also have it, or even having a UI to switch it on if there is a reason for some to have it off?