ManagedMqttClient - SubscribeAsync is misleading

[JaggerJo]

Confusing difference in behaviour between the IMqttClient and IManagedMqttClient:

IMqttClient.SubscribeAsync(..)

Immediately subscribes to a topic, exception on failure.

Topic is subscribed when the resulting task completes.

IManagedMqttClient.SubscribeAsync(..)

Adds the topic to the desired subscriptions, eventually subscribes. Does not throw on failure.

Topic is not subscribed when the resulting Task completes, subscription happens eventually.

Suggestion:

Rename IManagedMqttClient.SubscribeAsync(..) to IManagedMqttClient.SubscribeEventuallyAsync / EnqueueSubscribe.

Add IManagedMqttClient.SubscribeImmediateAsync(..) that only returns after a subscription has been established. This functionality is currently completely missing from the Managed Client. While it can be implemented by observing the SubscriptionsChangedAsync event it would be nice to have a clear distinction between subscribing now and subscribing eventually.