Add GPIO app and update CI (#5)

Apps/GPIO/main/Source/main.cpp

@@ -0,0 +1,44 @@
+#include <tt_app.h>
+#include "Application.h"
+
+static void onCreateApp(AppHandle appHandle, void* data) {
+    static_cast<Application*>(data)->onCreate(appHandle);
+}
+
+static void onDestroyApp(AppHandle appHandle, void* data) {
+    static_cast<Application*>(data)->onDestroy(appHandle);
+}
+
+static void onShowApp(AppHandle appHandle, void* data, lv_obj_t* parent) {
+    static_cast<Application*>(data)->onShow(appHandle, parent);
+}
+
+static void onHideApp(AppHandle appHandle, void* data) {
+    static_cast<Application*>(data)->onHide(appHandle);
+}
+
+static void* createApp() {
+    return new Application();
+}
+
+static void destroyApp(void* app) {
+    delete static_cast<Application*>(app);
+}
+
+ExternalAppManifest manifest = {
+    .createData = createApp,
+    .destroyData = destroyApp,
+    .onCreate = onCreateApp,
+    .onDestroy = onDestroyApp,
+    .onShow = onShowApp,
+    .onHide = onHideApp,
+};
+
+extern "C" {
+
+int main(int argc, char* argv[]) {
+    tt_app_register(&manifest);
+    return 0;
+}
+
+}