It would be nice to also list links between issues and Jenkins jobs using issue links.
For Jira Server this means implementing a issue-link-renderer: https://developer.atlassian.com/server/jira/platform/issue-link-renderer/ see also https://developer.atlassian.com/server/jira/platform/using-fields-in-remote-issue-links/ and https://developer.atlassian.com/server/jira/platform/jira-rest-api-for-remote-issue-links/. We can create a link using the RemoteIssueLinkManager.createRemoteIssueLink(RemoteIssueLink, ApplicationUser) where ApplicationUser can be null since we don't know the user when the system creates a link.
For Jira Cloud we just have the REST API where we can submit a link https://developer.atlassian.com/cloud/jira/platform/rest/v3/#api-rest-api-3-issue-issueIdOrKey-remotelink-post. Any images/icons used for cloud should load dynamically so that the latest job state can be shown without updating the link.