Be able to migrate the "mentioned on" information on C2C

Issue Summary

When performing a C2C migration, the "mentioned on" information was not showing when viewing an issue after the migration. 

Steps to Reproduce

1. Create a Jira project and a confluence space.
2. Create some issues on that project and insert the same Jira issues on the confluence pages.
3. After that, publish the confluence page and you will notice that the Jira issue will have a field called "mentioned on"  that refers the confluence page.
4. Migrate the project using the Jira cloud migration tool to a new instance.
5. Export the created space and import it on the new instance.

Expected Results

While accessing the issue, after the migration, the "mentioned on" information is showing while viewing the issue.

Actual Results

The "mentioned on" is not showing in Jira. 

Workaround

No workaround until the moment.