[FL-2254] IR: fix hardfault, correct remote loading (#999)

* Bugfix: remove freeing of uninitialized object (IrdaAppSignal).
Therefore rubbish in memory sometimes caused HardFault.
* Fix: slow FFF makes IR-remotes loading take much time,
so we can glimpse previous scene's view while remote is parsing.
Reproducing: remove remote, fast press back (while popup is playing)
and select new remote - previous popup view is displayed.

applications/irda/irda_app_remote_manager.cpp

@@ -110,10 +110,11 @@ std::string IrdaAppRemoteManager::get_button_name(uint32_t index) {
 }
 
 std::string IrdaAppRemoteManager::get_remote_name() {
-    return remote ? remote->name : std::string();
+    return remote.get() ? remote->name : std::string();
 }
 
 int IrdaAppRemoteManager::find_remote_name(const std::vector<std::string>& strings) {
+    furi_assert(remote.get() != nullptr);
     int i = 0;
     for(const auto& str : strings) {
         if(!str.compare(remote->name)) {

applications/irda/irda_app_signal.cpp

@@ -70,8 +70,6 @@ IrdaAppSignal::IrdaAppSignal(const IrdaAppSignal& other) {
 }
 
 IrdaAppSignal::IrdaAppSignal(IrdaAppSignal&& other) {
-    clear_timings();
-
     raw_signal = other.raw_signal;
     if(!raw_signal) {
         payload.message = other.payload.message;

applications/irda/scene/irda_app_scene_remote_list.cpp

@@ -15,6 +15,11 @@ void IrdaAppSceneRemoteList::on_enter(IrdaApp* app) {
         last_selected_remote.size() ? last_selected_remote.c_str() : nullptr;
     auto filename_ts = std::make_unique<TextStore>(IrdaAppRemoteManager::max_remote_name_length);
 
+    IrdaAppViewManager* view_manager = app->get_view_manager();
+    ButtonMenu* button_menu = view_manager->get_button_menu();
+    button_menu_reset(button_menu);
+    view_manager->switch_to(IrdaAppViewManager::ViewType::ButtonMenu);
+
     file_select_result = file_worker.file_select(
         IrdaApp::irda_directory,
         IrdaApp::irda_extension,