AKSubmission: Display a warning/require confirmation when AK title contains the word "AK"
Prefixing "AK" to AK titles makes them longer and harder to find in alphabetically sorted lists (since only some AKs have that prefix).
The Django validation logic should be used to show a warning and require a confirmation to inform people entering AKs about that issue.
A hint for the implementation can be found here: https://stackoverflow.com/questions/2270550/warnings-or-even-info-messages-instead-of-only-errors-in-django