Make the Git orgs/groups dynamic to the user

[etsauer]

When creating a new service from a software template, the template currently populates options from a hard-coded list in the template itself.. e.g. https://github.com/etsauer-acme/software-templates/blob/main/scaffolder-templates/quarkus-template/template.yaml#L65

In a real enterprise envrionment, we would want backstage to take in a user's PAT, and do some sort of evaluation to populate a list based on what orgs or groups a developer has access to. Not sure if this is possible, but something to look into later.