fix: properly handle CLI arguments (#2368)

Fix CLI arguments not being respected. This happened due to the addition of category-based logging (--help, --version) and changes to the window loading ( --channels), respectively.

When handling --channels, I took the liberty to refactor the previous version of window description (which relied on generating JSON) to directly building the WindowLayout.

src/singletons/WindowManager.hpp

@@ -23,6 +23,8 @@ enum class SettingsDialogPreference;
 class WindowManager final : public Singleton
 {
 public:
+    static const QString WINDOW_LAYOUT_FILENAME;
+
     WindowManager();
 
     static void encodeChannel(IndirectChannel channel, QJsonObject &obj);