Rename 'name' member of ActionDescription to 'customName'

* This is a deliberate break of compatibility since the field is now often
  empty, for non-markers. This means code will get a more explicit error when
  the name is being referenced, so it can be updated to fetch the name it needs
  as needed.

qrenderdoc/Windows/TimelineBar.cpp

@@ -1048,7 +1048,7 @@ uint32_t TimelineBar::processActions(QVector<Marker> &markers, QVector<uint32_t>
       markers.push_back(Marker());
       Marker &m = markers.back();
 
-      m.name = a.name;
+      m.name = a.customName;
       m.eidStart = a.eventId;
       m.eidEnd = processActions(m.children, m.actions, a.children);