Extend Node to support subscribing to a topic until a condition is met

[iche033]

Offer the ability to subscribe to a topic until some some conditions are met

One concrete example is that we want to subscribe to the pose topic until x > 0.

The idea is similar to std::condition_variable's wait_until function, where we can pass a predicate (function callback for evaluating conditions) to the function, and returns true when the requirements are met

Implementation suggestion

a) Extend SubscribeOptions to pass a predicate for evaluation conditions. Given that Node::Subscribe is non-blocking, we probably still want one final message callback to indicate that the conditions are met.
b) Alternatively, we could have a new blocking WaitUntil(topic, timeout, predicate) API function for this purpose.

Something to be careful of is that once the condition is met, the node would need to Unsubscribe to the topic. In this case, we should not stop subscription / remove other message handlers.