Spike: Investigate Nested controller traces

[hannahramadan]

The agent can produce two traces of similar names, a Nested/Controller/** and Controller/** trace. These are two separate metrics generated by the agent that can cause confusion.

The current understanding (link - internal) is that traces beginning with Nested represent the segment created as a result of a call coming from inside a controller, while traces beginning with Controller represent miscellaneous time that is a part of the controller's transaction, but that doesn't belong to a particular segment. The UI holds logic that will transform these two metrics into the same name, which is also confusing. For example:

Nested/Controller/api/inventory_transactions/show -> api/inventory_transactions#show
Controller/blogs/api/inventory_transactions/show -> api/inventory_transactions#show

We should spike to deepen our understanding of what causes these nested metrics to be created and followup with a solution that clarifies this for customers. Ideas:

• Better documentation
• UI feature request
• Code change

[workato-integration]

https://new-relic.atlassian.net/browse/NR-270996