Support OTEL span events

[jsumners-nr]

Following on from #3474, Span Events are effectively metadata on a span that we should propagate to New Relic. A span with event data will have an .events property set to an array of event objects:

• https://open-telemetry.github.io/opentelemetry-js/interfaces/_opentelemetry_sdk-node.node.ReadableSpan.html#events
• https://open-telemetry.github.io/opentelemetry-js/interfaces/_opentelemetry_sdk-node.node.TimedEvent.html

We need to update the our processing, as described in the above linked issue, to translate this event data and attach it to NR spans as so:

• type (string): must be set to SpanEvent.
• timestamp (number): milliseconds epoch relative. This must be derived from the event data, e.g. span.events[0].time. Our timestamp translator should be elevated to a general OTEL utility function and utilized to normalize the value.
• span.id (string): the identifier of the containing Span (span.context.spanId).
• trace.id (string): the trace identifier of the containing Span (span.context.traceId).
• name (string): the name of the event (e.g. span.events[0].name).

[Newrelic-Boomi]

https://new-relic.atlassian.net/browse/NR-482852