Offline mode

[tjkuson]

Expected behaviour

If I do not, for whatever reason, connect to the database from the client, I should be able to use the application in offline mode. This would mean I could access files that are already downloaded, but I cannot download, upload, or verify other files. Downloaded information should be available in the TOML files.

Current behaviour

If I do not connect to the database, I cannot access my locally downloaded library. It's downloaded and I can access the files through the file manager, but not through the application.