Rename Event.Status to Event.Condition to match v1beta3 agreement

Question - should this be a phase?  Seems like no, since phase implies
defined lifecycle and this field is explicitly not defined.

@lavalamp

Part of #1519 to allow roundtripping to v1beta3
As constant strings, I believe the case of these examples is correct.

OTOH, the comment for Reason, below, needs to be updated, both case and `s/status/condition/`