Messenger example - register, confirm, and unregister user facts

• Load user facts from client and update DB contact
• Register and confirm email fact
• Unregister email fact
• Register and confirm phone fact
• Unregister phone fact

Examples/xx-messenger/Tests/UserSearchFeatureTests/UserSearchFeatureTests.swift

 import ComposableArchitecture
 import ContactFeature
+import CustomDump
 import XCTest
 import XXClient
 import XXMessengerClient
@@ -64,6 +65,8 @@ final class UserSearchFeatureTests: XCTestCase {
       $0.failure = nil
     }
 
+    XCTAssertNoDifference(didSearchWithQuery, [.init(username: "Username")])
+
     store.receive(.didSucceed(contacts)) {
       $0.isSearching = false
       $0.failure = nil