* Force duties update on received blocks.
- Change the context on UpdateDuties to be passed by the calling
function.
- Change the context passed to UpdateDuties to not be dependent on a
slot context.
- Change the deadlines to be forced to be an entire epoch.
- Force duties to be initialized when receiving a HeadEvent if they
aren't already.
- Adds a read lock on the event handling
* review
* Add deadlines at start and healthyagain
* cancel once
dd9a5fba59