BLE Spam refactor again to use scene manager

applications/external/ble_spam/scenes/main.c

@@ -0,0 +1,16 @@
+#include "../ble_spam.h"
+
+void scene_main_on_enter(void* _ctx) {
+    Ctx* ctx = _ctx;
+    view_dispatcher_switch_to_view(ctx->view_dispatcher, ViewMain);
+}
+
+bool scene_main_on_event(void* _ctx, SceneManagerEvent event) {
+    UNUSED(_ctx);
+    UNUSED(event);
+    return false;
+}
+
+void scene_main_on_exit(void* _ctx) {
+    UNUSED(_ctx);
+}