Improve Co-Registrations

The user (Peter) which receives a DOI-Request should be informed about the fact that he gives the DOI to more then one email address (and other information)

e.g.

1. Doi-Sender Email(s)
2. Doi-Recipient Email
3. Link to nameID on a DOI explorerer where DOI(s) are stored (the dApp needs a "wallet" function which show's any DOI when querying a nameId. The NameId should be given by a query parameter.
4. additional data?
5. expiration date of DOI

See: https://github.com/Doichain/dapp/issues/9