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/ShaderMessageViewer.cpp

@@ -418,7 +418,8 @@ ShaderMessageViewer::ShaderMessageViewer(ICaptureContext &ctx, ShaderStageMask s
 
   ui->label->setText(tr("Shader messages from @%1 - %2")
                          .arg(m_EID)
-                         .arg(m_Action ? m_Action->name : rdcstr("Unknown action")));
+                         .arg(m_Action ? m_Ctx.GetEventBrowser()->GetEventName(m_Action->eventId)
+                                       : rdcstr("Unknown action")));
 
   setWindowTitle(tr("Shader messages at @%1").arg(m_EID));