Moved from_string functions and the mappings to an inl file so they don't horribly slow down the compilation on every file.

include/vulkan/vulkan_from_string.hpp

@@ -0,0 +1,20 @@
+// Copyright 2015-2023 The Khronos Group Inc.
+//
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+//
+
+// This header is generated from the Khronos Vulkan XML API Registry.
+
+#ifndef VULKAN_FROM_STRING_HPP
+#define VULKAN_FROM_STRING_HPP
+
+#include <optional>
+#include <string_view>
+#include <vulkan/vulkan_enums.hpp>
+
+namespace VULKAN_HPP_NAMESPACE
+{
+  template <typename TEnum>
+  extern std::optional<TEnum> from_string( std::string_view );
+}  // namespace VULKAN_HPP_NAMESPACE
+#endif