EventInspector replacement

Motto: keep the best of the two worlds.

Goals:
* keep EventBus simplicity, no need to implement iface methods (but using marker ifaces still needed)
* keep EventBus performance, by using Subscribe annotation and targeting exact event types (instead receiving all events)
* keep EventInspectors async capability (to have async event subscriber)
* keep EventInspectors simplicity, no need to litter EagerSingleton and EventBus registration, simply be "picked up and used" by host, just like EventInspectors were
* migrate existing EventInspectors to this host


CI
https://bamboo.zion.sonatype.com/browse/NX-OSSF88