Not always clear if instance or device version is meant

When the spec says something like "Requires Vulkan 1.1", it is not immediately clear if it means instance version, device version, or both.

Additionally, it is not readily clear which version satisfies dependency on a promoted extension. On top of it the spec hints some feature flags being disabled might not satisfy a dependency, but it is even less obvious if that is relevant somewhere yet without going into the rabbit hole and doing some guesswork. Ideally, all that should be autogenerated from XML into that "Requires ..." statement.

Also physical-device-level functionality adds little bit of confusion to this. E.g. if instance extension adds `vkGetPhysicalDevice*` command, and gets promoted to Vulkan 1.42, it is suggestive it would traditionally only need instance version 1.42, but careful reading of the spec hints that it actually needs device version.