Update the versions db on more juliaup operations

Minimally it should be updated before `juliaup update` is run.

But probably also before `juliaup status` is run. For that one we probably need some timeout story, at the moment `juliaup status` is completely offline and it would be good if it still worked in an offline scenario.

Not sure about other commands? In some way there is almost no harm in adding the update of the versions db to any operation that is already reaching out to the internet, I guess? So before say `juliaup add` as well?

Start by tracing the juliaup update, juliaup status, and juliaup add command paths to see where the versions database is accessed. Define which operations refresh it, and verify that status still works offline with an appropriate timeout. Done means the selected operations refresh reliably without breaking offline status behavior.

Written by the indexing model from the issue text.