VideoBackends/Vulkan: Use Vulkan loader and MoltenVK from Vulkan SDK on macOS

[OatmealDome]

Follow-up to #14492.

This allows us to drop our custom MoltenVK and switch to one that is pre-built. I've installed SDK 1.4.341.1 on the build machine.

I've also added support for KosmicKrisp in this PR, but I'll probably make it off-by-default before merging to avoid confusing users. I just wanted to have the CI create a build with KosmicKrisp enabled.

[OatmealDome]

Judging by FifoCI, it looks like the newer MoltenVK outputs renders that are more comparable to the other backends. Kirby Air Ride's shadows are not as dark, the crane shadow now renders in Lego Star Wars, and there is more depth of field(?) in Mario Kart Wii.

Edit: Dolphin was actually falling back to the Metal backend due to a lack of support for the Vulkan loader. Oops.

[OatmealDome]

Now supports FifoCI.

[TellowKrinkle]

Changes seem reasonable.

Just a heads up: when I tested on my M1 in macOS, in addition to MVK and KK, I was getting an entry for driver ID 26, which is HoneyKrisp (even though that should only be available on Linux). I think it's picking up an old copy of KK that I built and installed on my computer a while back. One slightly concerning thing is that the driver ID 26 ended up on the top of the list and selected by default. Should we be trying to ensure that we put our bundled drivers above random ones that might be found on the user's system?

[TellowKrinkle]

Suggested change

	driver = fmt::format("driver ID {}", fmt::underlying(properties_vk12.driverID));
	driver = fmt::format("Driver ID {}", fmt::underlying(properties_vk12.driverID));

Looks kind of weird IMO as the only thing not captialized in the entire list, e.g.

Apple M1 (driver ID 26)
Apple M1 (MoltenVK)
Apple M1 (KosmicKrisp)