Optional filtering for atmosphere environment light

[mate-h]

Objective

• Filtering always runs for the atmosphere
• Solari introduces a new use case where only mip 0 is sampled
• We need a way to disable the filtering to save on the overhead

Solution

• Add a bool field called filter on the AtmosphereEnvironmentMapLight struct.
• Generally updated documentation throughout

Testing

• Applied the change set from the still open PR Solari: Sample environment map light on miss #25704
• Created a new branch at https://github.com/mate-h/bevy/tree/m/solari-atmo-test
• I had to split the motion vector binding for denoising to fix solari on metal backend. will post a second PR for this.
• Ran the solari example with the AtmosphereEnvironmentMapLight filter field set to false.

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