Distinguish overall numberOfBTs vs the number of BTs which are ‘first class’

Distinguish overall numberOfBTs vs the number of BTs which are ‘first class’ eg not All Other Traffic.
From the standpoint of BT limits, All Other Traffic BTs do not count against the limit.

Could also report if a BT limit has been hit with the /events API call, filtered on AGENT_DIAGNOSTICS. Even if notifications are cleared on UI, this data will persist. (From Aaron Jacobs)

Start by tracing the existing numberOfBTs calculation and the /events API filtered on AGENT_DIAGNOSTICS. Confirm how first-class and All Other Traffic BTs are represented and define the expected limit-hit data; done means the reported counts and persistent diagnostic information distinguish these cases correctly.

Written by the indexing model from the issue text.