refactor: Make Args less of a singleton (#5041)

This means it's no longer a singleton, and its lifetime is bound to our application.
This felt like a good small experiment to see how its changes would look
if we did this.
As a shortcut, `getApp` that is already a mega singleton keeps a
reference to Args, this means places that are a bit more difficult to
inject into call `getApp()->getArgs()` just like other things are
accessed.

src/widgets/dialogs/LastRunCrashDialog.cpp

@@ -43,7 +43,7 @@ namespace chatterino {
 
 using namespace literals;
 
-LastRunCrashDialog::LastRunCrashDialog()
+LastRunCrashDialog::LastRunCrashDialog(const Args &args)
 {
     this->setWindowFlag(Qt::WindowContextHelpButtonHint, false);
     this->setWindowTitle(u"Chatterino - " % randomMessage());
@@ -62,14 +62,14 @@ LastRunCrashDialog::LastRunCrashDialog()
             "<a href=\"file:///" %
             reportsDir % u"\">" % reportsDir % u"</a>.<br>";
 
-    if (getArgs().exceptionCode)
+    if (args.exceptionCode)
     {
         text += u"The last run crashed with code <code>0x" %
-                QString::number(*getArgs().exceptionCode, 16) % u"</code>";
+                QString::number(*args.exceptionCode, 16) % u"</code>";
 
-        if (getArgs().exceptionMessage)
+        if (args.exceptionMessage)
         {
-            text += u" (" % *getArgs().exceptionMessage % u")";
+            text += u" (" % *args.exceptionMessage % u")";
         }
 
         text += u".<br>"_s;

src/widgets/dialogs/LastRunCrashDialog.hpp

@@ -4,10 +4,12 @@
 
 namespace chatterino {
 
+class Args;
+
 class LastRunCrashDialog : public QDialog
 {
 public:
-    LastRunCrashDialog();
+    explicit LastRunCrashDialog(const Args &args);
 };
 
 }  // namespace chatterino

src/widgets/dialogs/SettingsDialog.cpp

@@ -411,7 +411,7 @@ void SettingsDialog::showEvent(QShowEvent *e)
 ///// Widget creation helpers
 void SettingsDialog::onOkClicked()
 {
-    if (!getArgs().dontSaveSettings)
+    if (!getApp()->getArgs().dontSaveSettings)
     {
         getApp()->commands->save();
         pajlada::Settings::SettingManager::gSave();