Update context manager to store more than active segment

[bizob2828]

Description

When we built the context manager we had a legacy async local. Since legacy is removed we should update the context manager to be able to store more than just the active segment. Right now we have no easy way to arbitrarily store context info with context manager without stomping on the segment. this is because in transaction/tracer/index.js we assume all calls to contextManger.getContext() are only the active segment. Once we update we should update the work done in #2437 to use this instead of its own instance of AsyncLocalStorage. We could potentially use this to store other instrumentation data that we now do via symbols and a lot of roundabout instrumentation.

Acceptance Criteria

Update context manager to allow storage of more than just the active segment and update places that call contextManager.getContext() to properly extract the active segment in those instances

[workato-integration]

https://new-relic.atlassian.net/browse/NR-304390

[bizob2828]

I was looking into this for a different project. This branch updates context manager to add a new getSegment method. I still need to update to allow to mix-in other contexts