Resolve some flickering and state inconsistency due to overextended
observation of VPNProviderManager. Narrow down its scope to
VPNProviderServerView.
The downside of that, for now, is that servers are loaded "lazily late",
but this flow will make region selection from home easier.
Finally, show filters in popover on iPad.
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()
Davide