Disable `VULKAN_HPP_ASSERT_ON_RESULT` using CMake

[n0F4x]

The way to disable VULKAN_HPP_ASSERT_ON_RESULT is by defining it before including a Vulkan header.
I would like to disable it using CMake. (This is a cleaner approach, in my opinion.)
However, CMake doesn't support function-style preprocessor definitions, so there would have to be a new boolean definition instead for turning it on/off.

The worst use case comes with modules.
The user can't even define their own VULKAN_HPP_ASSERT_ON_RESULT, and is therefore stuck using the default.

[Zamundaaa]

You can define it as VULKAN_HPP_ASSERT_ON_RESULT=void in cmake

[asuessenbach]

@n0F4x Does the approach suggested by @Zamundaaa resolve your issue?

[n0F4x]

I couldn't figure out the difference between void and ((void)0) for assert. So, I don't know whether defining it as void might break something at some point.
Otherwise, it seems to work for me.