Initial integration of providers via API:
- Generic views and modifiers for provider/server selection
- Add in OpenVPNView
- Prepare in WireGuardView
Also:
- Introduce ProfileProcessor, move IAP processing there
- Move .asModuleView() to ModuleViewModifier for proper animation
- Use .themeModal() rather than .sheet()
Helps with automation. Install the VPN configuration before persisting a
profile, so that the 1:1 reference with OS settings is maintained.
Likewise, uninstall the VPN configuration after removing a profile.
This before-save hook also resolves a problem with multiple imports,
where multiple VPN permission alerts coalesce if no VPN configuration is
installed. Now the first import waits for the permission synchronously.
Fixes#618
Davide