Deprecate events API/SDK

[DylanRussell]

See open-telemetry/opentelemetry-specification#4319.

Events API/SDK are deprecated. The logs API/SDK should be used in it's place. An event is just a LogRecord with the event_name field set.

[rads-1996]

I would like to work on this issue. Can I please be assigned this?

[DylanRussell]

I've already done most of the work and sent out PRs and stuff for this, there isn't much left to do.. The PRs are currently blocked on #4676 (this will make logs usable as a replacement for events)