Migrates AudioVideoManagement to generated rtiddsgen API

Converts accessor calls to plain member access across avm service and plugin.

qt6-after/qt6-migrated-legatus/Lts/Services/AudioVideoManagement/exercise_context.cpp

@@ -36,7 +36,7 @@ ExerciseContext ExerciseContext::fromString(const QString &s)
   Q_ASSERT(s.startsWith(EX_PREFIX()));
 
   bool   couldConvert = false;
-  int    exerciseId = s.midRef(EX_PREFIX().size()).toInt(&couldConvert);
+  int    exerciseId = s.mid(EX_PREFIX().size()).toInt(&couldConvert);
   Q_ASSERT(couldConvert);
   return ExerciseContext(exerciseId);
 }