Allow manual triggering of full sync from Jira Connect App
When a GitLab namespace is added to the app config page in Jira, we trigger a one-time full sync of all the projects under that namespace.
We should also 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.