Store module preferences in the Profile.userInfo field for atomicity.
Access and modification are dramatically simplified, and synchronization
comes for free.
On the other side, fix provider preferences synchronization by using
viewContext for the CloudKit container.
Fixes#992
Formerly via blocks, now with final classes.
App:
- ProfileProcessor
- AppTunnelProcessor
- Implemented by DefaultAppProcessor in app
- Implemented by MockAppProcessor in UILibrary (for previews)
Tunnel:
- PacketTunnelProcessor
- Implemented by DefaultTunnelProcessor
Especially for flaky tests:
- Do objectWillChange.send() _before_ performing the change
- Send more events to .didChange to be more deterministic about test
expectations
