Cleanup unwanted properties in user profiles #663
Description
The class handling user profiles is called UserProfileHandler. This class accepts a UserProfileConfiguration holding a list of allowedProfileProperties.
Whenever a user profile is updated, only the properties defined in the allowedProfileProperties list are stored in the storage. However, when the property is already in the storage, it can never be removed because the PUT request to the storage is called with a ?merge=true parameter.
Because of this parameter, it is not possible to clean the user profile from properties which are not wanted anymore.