graphics: keep bounded image heaps resident in a bindless descriptor set

src/graphics/host_gpu/graphicContext.h

@@ -43,6 +43,7 @@ struct GraphicContext {
 	uint32_t                           min_subgroup_size                     = 0;
 	uint32_t                           max_subgroup_size                     = 0;
 	uint32_t                           max_push_descriptors                  = 0;
+	vk::DescriptorSetLayout            image_heap_layout                     = nullptr;
 	vk::ShaderStageFlags               required_subgroup_size_stages         = {};
 	Common::Mutex                      queue_mutex;
 	uint32_t                           queue_family = static_cast<uint32_t>(-1);