* Local contacts also start sharing again with imported user if they
were sharing with the old account
* Don't create empty contact entities for contacts which the imported
user doesn't share with and also maybe the contact doesn't share with
the importer
* Ensure people which were a contact in the archive still receive the
migration, even when the importer doesn't share with them, so they can
resend their contact message
fixes#8106 for real this time