public Map<ServiceInfo, Long> getServiceConfigGenerations(Application application, Duration timeoutPerService) {
        return getServiceConfigGenerations(application, timeoutPerService, new HostsToCheck(Set.of()));
    }
Fetches the active config generation for all services in the given application.
configserver/src/main/java/com/yahoo/vespa/config/server/application/ConfigConvergenceChecker.java