Ability to report on scratch org usage at a developer user level

[jonathankretzmer]

Describe the feature

In order to gain better visibility of the scratch orgs in use and which developer has fetched a particular scratch org, it would be very handy to have a field available that would gt set upon fetching a scratch org from the pool.

This would help us to:

1. Understand the utilisation of scratch orgs within our dev teams (over utilisation, not removing scratch orgs when complete with development)
2. Set up proactive notifications to inform developers about the expiry of scratch orgs they may be actively working on

Possible approach

At the same time as fetching a scratch org and updating the allocation_status__c field, set a new field that would store the username (or devhub User.Id) for the authenticated devhub user.

[azlam-abdulsalam]

Will reprioritize this in a later stage