Remove public ctors for QueueProperties/RuleProperties and add model factories instead

[JoshLove-msft]

Also add model factories for SubscriptionProperties/TopicProperties and all of the runtime property models.

[SeanFeldman]

What would be the obvious benefit of a factory over constructors?

[JoshLove-msft]

These types are not meant to be created by users in production scenarios. They are the return types when creating an entity, and also the input/output types when updating entities. The factories would be provided to support mocking.

[akScript]

does this mean in order to do a UpdateRuleAsync you have to call GetRuleAsync first to get the RuleProperties object?