Examples: GLFW: rework examples main loop to handle minimization without burning CPU or GPU by running unthrottled code. (#7844)

Backends: GLFW: added ImGui_ImplGlfw_Sleep() helper.

examples/example_glfw_vulkan/main.cpp

@@ -494,6 +494,11 @@ int main(int, char**)
             g_MainWindowData.FrameIndex = 0;
             g_SwapChainRebuild = false;
         }
+        if (glfwGetWindowAttrib(window, GLFW_ICONIFIED) != 0)
+        {
+            ImGui_ImplGlfw_Sleep(10);
+            continue;
+        }
 
         // Start the Dear ImGui frame
         ImGui_ImplVulkan_NewFrame();