Support high-volume events.

[davinchia]

This is probably part of a larger conversation for when larger pieces of our organisation require events that aren't strictly tied to api resources. Opened here for tracking purposes.

An example of this is the real time distribution api, which is slated to support events of hundreds and thousands requests/s. Emitting all of that into a common topic is unwieldy and costly. Subscription filtering can help reduce load but can be difficult to configure correctly.

We should explore an alternative model with tighter more configurable scopes for easy management and efficiency, and integrate this with Reslang and the api-specs tooling.

[davinchia]

Fyi @ajain0184