assets/save: Add origin browse link only for valid visit statuses
In the Save Code Now Web UI, add the link to browse a saved origin only if the visit status is valid.
This prevents to browse the saved origin when loading data are not yet available in storage database (replication lag for instance).
Related to #3848 (closed)
Depends on !707 (closed)
Migrated from D7044 (view on Phabricator)