Implement pattern-based subscriptions

[ecorm]

Implement pattern-based subscriptions, as per the advanced spec.

[ecorm]

Requirements on client:

• HELLO.Details.roles.subscriber.features.pattern_based_subscription|bool := true
• SUBSCRIBE.Options.match|string := "prefix"
• SUBSCRIBE.Options.match|string := "wildcard"
• Client must be prepared to receive EVENT.Details.topic|uri, which is the original PUBLISH.Topic

From spec:

When a single event matches more than one of a Subscriber's subscriptions, the event will be delivered for each subscription. The Subscriber can detect the delivery of that same event on multiple subscriptions via EVENT.PUBLISHED.Publication, which will be identical.

There should therefore be no special handling involved when the client dispatches events to handlers, nor when it comes to subscription management.