Enabling render and viewport denoising is now both done from the render
properties. View layers still can individually be enabled/disabled for
denoising and have their own denoising parameters.
Note that the denoising engine also affects how denoising data passes are
output even if no denoising happens on the render itself, to make the passes
compatible with the engine.
This includes internal refactoring for how denoising parameters are passed
along, trying to avoid code duplication and unclear naming.
Ref T76259
0a3bde6300