Remove the context argument from the event methods. It is unused and can
be added back in as a passed option if needed in the future.

Update AddEvent to accept a required name and a set of options. These
options are the new EventOption type that can be used to configure a
SpanConfig Timestamp and Attributes.

Remove the AddEventWithTimestamp method as it is redundant to calling
AddEvent with a WithTimestamp option.

Update RecordError to also accept the EventOptions.

Use the LifeCycleOption to encapsulate the options passed to a span for
life cycle events.