Userfiles 'show' page to provide full path of cache locations on remote bourreaux too

[prioux]

When accessed as an admin user, the userfiles 'show' page currently provides the path of the userfile on the data provider side and on the portal cache side.

Sometimes when investigating a file on a remote bourreau we'd like to see where exactly it is cached over there. The 'show' page could be extended to provide the cache location on any remote bourreaux (or portals) where there is a SyncSattus object indicating that some data is present in the cache.