Add artifact enrollment for dockerhub

[JAORMX]

Please describe the enhancement

This proposes adding an artifact registration workflow to minder.

Solution Proposal

This proposes adding an artifact register subcommand which will register an artifact or container for dockerhub into minder.

Describe alternatives you've considered

No response

Additional context

This is needed because dockerhub doesn't have the ability to get events for artifacts being added or removed, so we need to explicitly track them in minder

Acceptance Criteria

No response