Examples: Fix for Emscripten. GLFW+WGPU: rework examples main loop to handle minimization. (#7844)

Amend 8874787, 71ee2ce
Amend ea39841f (emscripten_mainloop_stub.h)

examples/example_glfw_wgpu/main.cpp

@@ -151,6 +151,11 @@ int main(int, char**)
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
         glfwPollEvents();
+        if (glfwGetWindowAttrib(window, GLFW_ICONIFIED) != 0)
+        {
+            ImGui_ImplGlfw_Sleep(10);
+            continue;
+        }
 
         // React to changes in screen size
         int width, height;