Add streetlight service that turns mqtt streetlight publish actions to events

[bmaidics]

In order to make the demo more compelling, we should add a service that turns mqtt streetlight publish actions to events, so we don't need to modify the original streetlight asyncapi yaml.

[jfallows]

Note: this should be an mqtt service simulating the streetlight IoT device.

Therefore, we need a service-perspective AsyncAPI documents as well as a client-perspective AsyncAPI documents to fully support the scenario without needing to change the client-perspective AsyncAPI documents we already have.

Note: it may be possible to create each service-perspective AsyncAPI document by simply inverting the polarity of send and receive operations, so for now we assume that is the case and that it happens outside zilla.