Add events on camera status changes
Trying to retranscrit a feature request from @sebastien.petitdemange:
Clients such as Bliss have not choice but polling on the camera status (e.g.
Ready) before (soft) triggering a new image with
startAcq. A better solution would be to have events fired for camera status changes.
This might be easy to implement or not depending on the underlying SDKs. So adding a new camera capability might be required. Or we could choose to emulate this and do the polling in the camera plugin.