Add a confirmation modal warning the user about unsaved changes in Pipeline Editor
Problem
It's possible to start making changes to your pipeline config in the Pipeline Editor and accidentally close the tab, or forget you made the changes. We should prevent users from losing their changes.
Proposal
If user has unsaved changes and somehow navigates off the page, we should show a modal that says something like: "The pipeline configuration has unsaved changes. Are you sure you want to close the editor? - Yes, No".
We should use the small modal component for this. https://design.gitlab.com/components/modal or the system modal if necessary.
Edited by Nadia Sotnikova