[ENHANCEMENT] Support Span Event Attributes in the UI

[nick-kang]

Is your feature request related to a problem? Please describe.
Span events only show the message and not the attributes in the UI

Describe the solution you'd like
Show span event attributes in the UI

Describe alternatives you've considered
We'd like to consolidate tracing infrastructure and are running a Jaeger instance and Phoenix instance.

Additional context
Add any other context or screenshots about the feature request here.

[axiomofjoy]

Thanks @nick-kang for the feedback. Curious what sort of debugging flows you use in Jaeger that you are hoping to switch to Phoenix?

[mikeldking]

Hey @nick-kang - thanks a lot for the feedback. Agree we should show this. We are curious however how you are using events today - would love to hear from you so that we can build a better UX for your use-case!