Add support for multiple credentials when sending invitation from admin dashboard

[esune]

When using the administrative web application to generate user invites and having more than one credential configured in the controlled and available to being issued, the administrator should be able to pick which credential to issue when sending out the invite.

The issuer web application would then receive this information in the invite, alongside the rest of the data, and request the appropriate credential when starting the issuance process.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically closed because it has become stale.