Fix a few compiler warnings and startup/validation issues at runtime (#1193)

* Add error recovery to trianglevulkan13 and fix missing "override" compiler warnings

* Look for vkGetPhysicalDeviceFormatProperties2KHR in hostimagecopy example

* Enable fragmentStoresAndAtomics feature to avoid VVL warning in subpasses example

examples/subpasses/subpasses.cpp

@@ -99,6 +99,8 @@ public:
 		camera.setRotation(glm::vec3(0.5f, 210.05f, 0.0f));
 		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);
 		ui.subpass = 2;
+
+		enabledFeatures.fragmentStoresAndAtomics = VK_TRUE;
 	}
 
 	~VulkanExample()