- Address further restrictions on actor-isolation by using `nonisolated`
on:
- Combine subjects
- Core Data context/controller
- Blocks
- In previews using inline `@State`, create a custom view instead
- Use `@retroactive` in l10n extensions
- Fix compile error in WireGuardKit
Countries are filtered through the latest servers list. If a country is
chosen, the countries picker only lists the currently selected country,
because there are no servers from other countries.
Update the library to prefetch the available countries per category.
Also, improve filters by constraining related fields:
- Pick countries from the filtered category
- Pick presets from those available in the currently filtered servers
Closes#705