fix: implement PR suggestions

Some stylistic changes, and get hashes from the mod providers when
building the metadata.

launcher/Application.cpp

@@ -644,7 +644,7 @@ Application::Application(int &argc, char **argv) : QApplication(argc, argv)
         m_settings->registerSetting("MCLaunchMethod", "LauncherPart");
 
         // Minecraft mods
-        m_settings->registerSetting("DontUseModMetadata", false);
+        m_settings->registerSetting("ModMetadataDisabled", false);
 
         // Minecraft offline player name
         m_settings->registerSetting("LastOfflinePlayerName", "");