Display a "Last Duo activity" Date in the Duo Users table on the Usage Quota page

Problem

A common metric requested by customers & prospects is the ability to understand which of the users assigned a license are making use of that license (ec. date of last use of Duo per user, number of Duo requests for each user over a period of time). They want to be able to reallocate under used licenses to other users.

Our team is running a Duo POV with [insert large customer]. One of their primary concerns is the lack of visibility into which assigned users are using the Duo licenses and how frequently they are interacting with Duo. This is to ensure they are maximizing efficiency with their allocated seats.

Proposal

• Add a new lastDuoActivityOn field to the users api, which stores the last time an AI feature was used.
• Extend the EventTracking module to update the aforementioned field. This captures usage for all AI features except for code suggestions and duo workflow.
• Additionally update lastDuoActivityOn when the JWT token refresh occurs to account for code suggestion and duo workflow events.
• frontend work will be done in Display last GitLab Duo add-on activity on Duo ... (#455761 - closed)