Support for AysncAPI

[rob-metalinkage]

Consider implementation of asyncAPI version of OGC API Processes:

https://swagger.io/blog/using-event-driven-asyncapi-specifications-with-sw/

OGC API processes has an asynchronous mode, but there is now an emerging approach with tool support.

Has anyone considered how hard it would be to implement this in pyGeoAPI and submit an asyncAPI profile of OGC API Processes as a standard?

[tomkralidis]

@rob-metalinkage note that was implemented via #2220 at the OGC Code sprint in Fort Collins and available per https://docs.pygeoapi.io/en/latest/pubsub.html#asyncapi

[rob-metalinkage]

Cool, I did google looking for evidence but nothing came up.