WICKET-5178 StopPropagation functionality on link is broken

Add an additional setting for JavaScript stopPropagation functionality
WICKET-5178 StopPropagation functionality on link is broken
WICKET-5178 StopPropagation functionality on link is broken
WICKET-5093 The event listener in Wicket.Ajax.ajax() should not return the value of attrs.ad (allowDefault)
WICKET-5186 Use arrays instead of String concatenation in JavaScript for better performance
WICKET-5178 StopPropagation functionality on link is broken
new ajax attribute added to test