[SER] Diagnose and validate illegal use of HitObject in unsupported contexts

[simoll]

Tracking bug to implement HLSL and DXIL diagnostics/validation for HitObject in unsupported contexts:

• Add HLSL error diagnostics for HitObject in cbuffer and global declarations
• Add DXIL validation rules to block HitObject in memory buffers, in groupshared memory, in ray payloads, or in intersection attributes.