Add stability/deprecation to events (log_events)

[lmolkova]

We don't render stability/deprecation status of events.

As events/log_events work continues, it would be great if we could require stability on events and supported deprecating them. We should be able to see the status in the markdown.

Update: we should also add events to compatibility check and prevent them from being deleted.

[MSNev]

Agree, its probably also related to #259