Each time I run a migration, roles are unnecessarily duplicated

Issue Summary

When a role is migrated using JCMA, there are situations where roles are migrated again with a <role_name> + (migrated) appended to each subsequent migration. This causes a lot of post-migration cleanup. The de-duplication process is tedious & risky as all of the duplicated role references in (multiple) project settings needs to be carefully remapped to the original role before deleting the duplicates. This gets onerous when many roles and projects are migrated.

Steps to Reproduce

1. Run a migration with a few projects
2. When a role is migrated the first time along with these first few projects, the Jira Cloud Migration Assistant records the mapping and for subsequent migrations, it re-links to the role as per https://confluence.atlassian.com/cloud/how-the-jira-cloud-migration-assistant-links-your-data-993925217.html
3. At times, Atlassian Support may be contacted for troubleshooting and the mapping logic (scope table) is reset
4. This the results in <role_name> + (migrated 2)... and then (migrate 3), (migrated 4) each time the mapping logic is reset
5. De-duplicate roles in Cloud post-migration.

Expected Results

 We are conducting customer interviews to develop improvements to:

• Default behaviour as documented in https://confluence.atlassian.com/cloud/how-the-jira-cloud-migration-assistant-links-your-data-993925217.html 
• <role_name> + (migrated) being appended often results from re-migration or clean up situations where roles are being deleted and then migration scope tables are reset by Atlassian Support. We expect this to be mostly addressed in MIG-163 Better handling of deleted objects with the Jira Cloud Migration Assistant
• Potential improvements to enable you to make a decision on whether to merge an object or not. Our current defaults are designed so that the migration does not disturb existing data already in your Jira Cloud site ie. by default we currently do not perform data merges on unrelated objects

Please comment if you have use cases you would like us to consider.