When a GitLab namespace is added to the app config page in Jira, we do not sync existing data. We should maybe trigger a sync for data up to a certain point either by time (certain months ago?) or by number (last X number of MRs / commits). For now we only want to sync merge request data because it is easier to retrieve from the database. In the next iteration we will also [sync branches and commit data](https://gitlab.com/gitlab-org/gitlab/-/issues/263240) We should also probably allow users to manually trigger a re-sync in the config page. We should also consider adding sync status indicator here to show if a sync is in progress. Also, I think we shouldn't allow multiple syncs at the same time for the same namespace.