Outside Collaborator Tracking

[mikegrima]

A feature should be added to track the outside collaborators of repositories, and a "first seen", or "approved" date, which can be used for access lifecycle and security.

Effectively, I would like to see the following features:

1. Track an outside collaborator for a given repository
2. Provide a date as to when the outside collaborator was first seen for a repository
3. Provide a date as to when the outside collaborator has last been verified as requiring access to a given repository
4. Provide a name of the user/employee that added the outside collaborator, and last approved their access
5. Provide an API or equivalent so that scripts have the ability to fetch and alter this information in an authenticated manner

The features above should allow scripts to automatically boot outside collaborators from a repository after a given time period if their access has not been verified as necessary. This would also permit scripts/bots/tools/etc. to provide an interface for users to manually approve of the outside collaborator's access to the repository.