chore: remove Singleton & replace getIApp with getApp (#5514)

src/controllers/accounts/AccountController.hpp

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "common/SignalVector.hpp"
-#include "common/Singleton.hpp"
 #include "providers/twitch/TwitchAccountManager.hpp"
 
 #include <QObject>
@@ -14,14 +13,17 @@ class Paths;
 
 class AccountModel;
 
-class AccountController final : public Singleton
+class AccountController final
 {
 public:
     AccountController();
 
     AccountModel *createModel(QObject *parent);
 
-    void initialize(Settings &settings, const Paths &paths) override;
+    /**
+     * Load current user & send off a signal to subscribers about any potential changes
+     */
+    void load();
 
     TwitchAccountManager twitch;