Improve ADO listing

Overview

At the moment when ADO Project has no repository or disabled / uninitialised repositories we skip it, however with support of ADO Board we may run into situation when ADO project where only Boards service is used.

Tasks

• Update docs if needed (workflow, runbooks, README, migration metrics, etc.)

Acceptance Criteria

• Existing UTs pass locally
• 100% code coverage on new code

@gitlab-org/professional-services-automation/tools/migration