Add back extmainapps

applications/services/loader/loader_extmainapp.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <gui/icon.h>
+#include <m-list.h>
+
+typedef struct {
+    const char* name;
+    const char* path;
+    const Icon* icon;
+} ExtMainApp;
+
+LIST_DEF(ExtMainAppList, ExtMainApp, M_POD_OPLIST)
+
+ExtMainAppList_t* loader_get_ext_main_apps(Loader* loader);