Update Child Collections Mapping, set Cascade style to both All and Delete Orphan.

Enables deletion of items that has been removed from the collection when saving/updating parent item. With only cascade all the following user account service method will not work (Child collection item will not be deleted):

- RemoveCertificate
- RemoveClaim
- RemoveClaims
- RemoveLinkedAccount
- RemoveLinkedAccountClaims
- RemovePasswordResetSecret
- RemoveTwoFactorAuthTokens