ISIS-1722: upgrades Wicket to 7.9.0, and WicketStuff to 7.8.1
ISIS-1722: upgrades Wicket to 7.9.0, and WicketStuff to 7.8.1

incodehq/isis,incodehq/isis,apache/isis,oscarbou/isis,estatio/isis,apache/isis,oscarbou/isis,incodehq/isis,apache/isis,apache/isis,oscarbou/isis,oscarbou/isis,estatio/isis,incodehq/isis,estatio/isis,estatio/isis,apache/isis,apache/isis