Refactor VaadinHotswapper methods to take a single event paramter

[mcollovati]

VaadinHotswapper defines methods that take several parameters, like VaadinService, set of changed classes, redefine flag.
It would be good to refactor them to take a single parameter that encapsulates all the required information, to simplify refactorings avoiding breaking changes.
Existing methods can be deprecated, and the default implementation of new methods can delegate to them until they are removed.

    record HotswapEvent(VaadinService, Set<Class<?>>, redefined);
    default boolean onClassLoadEvent(HotswapEvent event) {
         return onClassLoadEvent(event.service, event.classes, event.redefined)
    }

    record HotswapSessionEvent(VaadinSession) extends HotswapEvent;
    default boolean onClassLoadEvent(HotswapSessionEvent event) {
         return onClassLoadEvent(event.session, event.classes, event.redefined)
    }