fix: deadlock and use-after-free in tests (#4981)

* fix: use-after-free in settings

* refactor: put seventv api into a singleton

* chore: add changelog entry

* Add warning for when the 7TV load fails

src/Application.cpp

@@ -10,6 +10,7 @@
 #include "controllers/hotkeys/HotkeyController.hpp"
 #include "controllers/ignores/IgnoreController.hpp"
 #include "controllers/notifications/NotificationController.hpp"
+#include "providers/seventv/SeventvAPI.hpp"
 #include "singletons/ImageUploader.hpp"
 #ifdef CHATTERINO_HAVE_PLUGINS
 #    include "controllers/plugins/PluginController.hpp"
@@ -81,6 +82,7 @@ Application::Application(Settings &_settings, Paths &_paths)
     , windows(&this->emplace<WindowManager>())
     , toasts(&this->emplace<Toasts>())
     , imageUploader(&this->emplace<ImageUploader>())
+    , seventvAPI(&this->emplace<SeventvAPI>())
 
     , commands(&this->emplace<CommandController>())
     , notifications(&this->emplace<NotificationController>())