Rename function getHeaderFlashMessagesForCurrentPid() in PageLayoutController to reflect that callouts are used and not flashmesseages
see explanation in
- flash messages: those are normally shown after an action, e.g saving something was succesful
- callouts: give the user permanent feedback
Could be renamed to getCalloutsForCurrentPid().
Since PageLayoutController is non-internal I assume this is a breaking change, so cannot be done until v12.