[APM] [OTel] Transaction and Span Flyout for OTel data

[AlexanderWert]

Span and Transaction Flyouts do not differentiate between classic APM data and OTel-native data.
The result is that it shows

• all the fields (including aliases) that are then shown as duplicates
• it does not differentiate between different categories of fields

With OTel-native data we have the chance to create a more appealing experience for these flyouts by explicitly differentiating between attributes, resource attributes, scope attributes and OTLP native fields.

[elasticmachine]

Pinging @elastic/obs-ux-infra_services-team (Team:obs-ux-infra_services)