[DirectX] Implement Shader Flag Analysis for `SamplerDescriptorHeapIndexing`

[bharadwajy]

Set the function-level flag if OpCode::CreateHandleFromHeap is used with non-zero sampler value. This is named m_bSamplerDescriptorHeapIndexing in DXC sources. See here for reference.

AC:

Add tests to verify correctness of analysis.

[damyanp]

Probably should be combined with #116134