Support exporting event_name using OTLP Exporter

[lalitb]

As the OTLP Protocol now supports exporting EventName, updates will be needed in the otel-cpp OTLP exporter to include support for exporting EventId::name.

This is placeholder issue, to be implemented once otel-proto 1.5.0 is published

[marcalff]

opentelemetry-cpp is already upgraded to use opentelemetry-proto 1.15.0.

[github-actions]

This issue is available for anyone to work on. Make sure to reference this issue in your pull request.
✨ Thank you for your contribution! ✨

[perhapsmaple]

Hi,I would like to work on this. I see that the OTLP Log Recordable already has a method that can be used for this:
void SetEventId(int64_t /* id */, nostd::string_view /* name */) noexcept override;

There is one problem that I can see with this, id is not implemented in the proto. Is it alright to ignore id and set the event_name field?

[lalitb]

@perhapsmaple thanks for volunteering for this. Yes it should be fine to only populate event_name.