[Backport 21.2][HDRP] Backport various PRs

[sebastienlagarde]

Purpose of this PR

• Add missing DisallowMultipleComponent attribute in AdditionalData components Add missing DisallowMultipleComponent attribute in AdditionalData components #5859
• [HDRP][Path Tracing] Slight robustness improvement for sample rescaling [HDRP][Path Tracing] Slight robustness improvement for sample rescaling #5800
• recaptured reflection probes, updated normals on 2nd room's floor (HDRP Template - Fixed reflection probes and floor normals  #5873)
• Hair Documentation Pass (Hair Documentation Pass #5868)
• [HDRP] Remove Fake GTAO bounce on the occlusion when used for direct lighting [HDRP] Remove Fake GTAO bounce on the occlusion when used for direct lighting #5836

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[github-actions]

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