Add methods consuming Collection for Subscribe/UnsubscribeBuilder

[SgtSilvio]

No description provided.

[MicWalter]

Motivation:
It should be easy to add a dynamic amount of topics to a Subscribe/Unsubscribe packet.

Problem:
At the moment for each Mqtt5Subscription/Mqtt5Unsubscribe you need to call addSubscription()/addTopicFilter(), that means you can't easily create a Subscribe/Unsubscribe packet that has a random amount of subscriptions/unsubscriptions.

Example:
Subscribe

final Mqtt5Subscribe subscribeMessage = Mqtt5Subscribe.builder()
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .addSubscription(Mqtt5Subscription.builder().topicFilter(topic).qos(MqttQoS.AT_LEAST_ONCE).build())
               .build();

Unsubscribe:

        subscriber.unsubscribe(Mqtt5Unsubscribe.build()
                .addTopicFilter("unsub1")
                .addTopicFilter("unsub2")
                .addTopicFilter("unsub3")
                .addTopicFilter("unsub4")
                .addTopicFilter("unsub5")
                .addTopicFilter("unsub6")
                .build())
                .doOnSuccess(success -> {
                    System.out.println("unsuback success; reason code: " + success.getReasonCodes().toString());
                })
                .doOnError(error -> System.out.println("error"))
                .subscribe();

Proposed changes:
You can give the methods addSubscription()/addTopicFilter() a List as parameter.

Example:
Subscribe

        ImmutableList<Mqtt5Subscribe> topics = createTopicsForRole(clientID);

        final Mqtt5Subscribe subscribeMessage = Mqtt5Subscribe.builder()
                .addSubscription(topics)
                .build();

Unsubscribe

        ImmutableList<String> unsubTopics = getTopicsToUnsubscribeForNewGeoPosition();

        subscriber.unsubscribe(Mqtt5Unsubscribe.build()
                .addTopicFilter(unsubTopics)
                .build())
                .doOnSuccess(success -> {
                    System.out.println("Removed obsolete geo position topics; reason code: " + success.getReasonCodes().toString());
                })
                .doOnError(error -> System.out.println("error"))
                .subscribe();

[SgtSilvio]

Method names:

• SubscribeBuilder: addSupscriptions
• UnsubscribeBuilder: addTopicFilters

Also add an addAll method to Mqtt5UserPropertiesBuilder

[SgtSilvio]

Resolved by #290