[Users] Add a "last active" column on the users overview page

[netsensei]

As an administrator, I can see a "last active" column on the users overview page. This column allows me to see when an account was last active on the hub: that is last log in.

Detailed description

This feature allows administrators to see which accounts are inactive for an extended period of time and need to be either disabled or removed. This allows for better management of stale accounts which could be a potential security hazard.

Possible implementation

• When a user logs in, update a value in a field "lastLogin"
• As an administrator, I can see a "last active" column on the users overview page showing the datetime of the last log in.