Behavior of "Replace" and "Delete" buttons on blob page is inconsistent with "Edit" button

The "Replace" and "Delete" buttons should show the same behavior that the "Edit" button does as of https://gitlab.com/gitlab-org/gitlab-ce/issues/28899 / https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10233, showing a modal to ask the user to Fork instead of forking automatically.

Since the feature reduces internal consistency between buttons that are directly adjacent, I think this is a regression.