Introduce helper function ResultValue<UniqueHandle<Type, Dispatch>>::asTuple()

Allows coding like this:

    vk::Result         result;
    vk::UniquePipeline pipeline;
    std::tie( result, pipeline ) =
      device->createGraphicsPipelineUnique( nullptr, graphicsPipelineCreateInfo ).asTuple();

vulkan/vulkan.hpp

@@ -16369,8 +16369,10 @@ namespace VULKAN_HPP_NAMESPACE
       , value( std::move( v ) )
     {}
 
-    Result                       result;
-    UniqueHandle<Type, Dispatch> value;
+    std::tuple<Result, UniqueHandle<Type, Dispatch>> asTuple()
+    {
+      return std::make_tuple( result, std::move( value ) );
+    }
 
 #  if !defined( VULKAN_HPP_DISABLE_IMPLICIT_RESULT_VALUE_CAST )
     VULKAN_HPP_DEPRECATED(
@@ -16387,6 +16389,9 @@ namespace VULKAN_HPP_NAMESPACE
       return std::move( value );
     }
 #  endif
+
+    Result                       result;
+    UniqueHandle<Type, Dispatch> value;
   };
 
   template <typename Type, typename Dispatch>