View source for Data migration using Export/Import

'''Use case''': Move data from one user and tenant to another, as a way of renaming a user and tenant

'''Solution''': Use the Export/Import functionality

'''Steps''':

* Register new users
* Export activities (creator)
* Export things (for all followers)
* Delete things
* Delete activities
* Delete topics
* Create topics (send simulation | new topic)
* Import activities in the new creator
* Publish activity
* Subscribe follower admin to service
* Import things (for all followers)
* Invite other followers with actors
* Delete old users and tenants