Allow for enrollment of DockerHub

[JAORMX]

Please describe the enhancement

The idea is to get minder to do an enrollment with a dockerhub-provided token. We need to add the necessary bits and pieces for the provider configuration to go through and the token installed in minder in such a way that we can make authenticated calls to dockerhub.

Solution Proposal

This will change/add a CreateProvider GRPC call that does the above.

Describe alternatives you've considered

No response

Additional context

No response

Acceptance Criteria

No response