Bug: public links should only be created for one credential

[alexfigtree]

Describe the bug
The same public links are being created for credentials that have the same cred name and issuance date.

Background Info
The "public" link pill that shows next to the "verified" pill on a dashboard for each credential is what indicates that a public link has been created for that credential. Any public link created should only correspond to one credential. Question for this created issue is whether or not this is a real bug or if we expect this replication of public links to be acceptable for other situations (adding the same credential to multiple profiles, for example).

To Reproduce
Steps to reproduce the behavior:

1. Go to Settingsl
2. Click on About
3. Click on version
4. Click on Add mock credentials
5. Add the same mock credential twice (assuming one profile)
6. Confirm that there are two identical credentials on your dashboard that have the same cred name and issuance date
7. Open one and click share (three dots, upper right hand corner)
8. On share page, create public link
9. Go back to dashboard and see 1)"Public" pill label is now showing on both edited credential and the one, and 2) both have public links created for them.

Additional context
Any public link created should only correspond to one credential. Need to confirm that app is working as expected. Questions for devs regarding duplication of credentials and expectations.