Changing shader macro from feature settings

[Pentalimbed]

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Akin to static switching in UE4, and preprocessor definitions from ReShade, allowing features to def or undef macros for specific shaders and recompile on the fly. Better performance, as opposed to having dynamic branches in shader code.

[alandtse]

There is some progress toward this with the ability to set global defines in Advanced. Some things to add.

• [ ] Compute shader reloading.
• [x] Framework to selectively define shaders based on types (lighting)
• [ ] Framework for define configuration from features