[FL-2284] IR: Show universal remote loading (#1004)

* [FL-2131] IR: Show universal remote loading
* Remove unused hal rtc. Gui: cleanup loading module.

Co-authored-by: あく <alleteam@gmail.com>

applications/gui/modules/loading.h

@@ -0,0 +1,35 @@
+#pragma once
+#include <gui/view.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Loading anonymous structure */
+typedef struct Loading Loading;
+
+/** Allocate and initialize
+ *
+ * This View used to show system is doing some processing
+ *
+ * @return     Loading View instance
+ */
+Loading* loading_alloc();
+
+/** Deinitialize and free Loading View
+ *
+ * @param      instance  Loading instance
+ */
+void loading_free(Loading* instance);
+
+/** Get Loading view
+ *
+ * @param      instance  Loading instance
+ *
+ * @return     View instance that can be used for embedding
+ */
+View* loading_get_view(Loading* instance);
+
+#ifdef __cplusplus
+}
+#endif