Attempt to improve unit test reliability:

- synchronize mock properties on the main queue
- sleep for longer when processing routes
- finish encoding before deallocating the keyed archiver
- wait for NotificationCenter notifications to be delivered
- change were we process remote notification permissions

UnitTests/Sources/NotificationManager/MockCoder.swift

@@ -17,6 +17,10 @@
 import Foundation
 
 final class MockCoder: NSKeyedArchiver {
+    deinit {
+        finishEncoding()
+    }
+    
     override func decodeObject(forKey _: String) -> Any { "" }
     override func decodeInt64(forKey key: String) -> Int64 { 0 }
 }