* Fix various bugs in opvault parsing to include: TOTP parsing, date handling, naming convention, attachments, and multiple url's.
* Remove category groups that don't have any entries.
* Simplify tests by focusing on the resulting database instead of the parsing mechanics.
* Remove proprietary "freddy" opvault in favor of self-made "keepassxc" opvault.
* Fix#4069, select opvault file on macOS
