refactor: strip existing project when adding it to an organization

[shreddedbacon]

General Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated
• PR title is ready for inclusion in changelog

Database Migrations

• If your PR contains a database migation, it MUST be the latest in date order alphabetically

There exists a condition when adding an existing project to an organization that could result in a project and any groups it has being left in a disconnected state. This refactor is to make sure that the project and any access it previously had is stripped entirely when adding the project to the organization. Effectively it would appear as a fresh project (still retaining all of its environments etc. though)