[Cin] Various HDR gamma encoding in shaders

[Andrew Randrianasulu]

HLG might be badly missing.

https://reshade.me/forum/shader-discussion/7817-how-to-make-hdr-work-in-shaders

*I think* right now cingg does not do any PQ/HLG de/encoding, so blend
modes with HDR most likely will not work correctly (they need linear light).
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