Add the ASS sub document and the ASS tree

Also add views for the ASS tree in read only mode for now

src/Lib/Ass/AssFactory.cc

@@ -15,7+15,7 @@
     QStringList eventsContent{};
 
     while (!in.atEnd()) {
         const QString line = in.readLine().trimmed();
 
         // Dectect comment
         if (line.startsWith(";") || line.isEmpty()) {
@@ -69,7+69,7 @@
         qCritical() << "Failed to create ASS style or events with error:" << e.what();
     }
 
+    qDebug() << "Got" << assLines.size() << "ASS dialog lines";
+
     return true;
 }