[test] perf(tests): extract virtual DelayAsync in AddTrustedClientViewModel and override in tests

Author: marwannettour

src/ByteSync.Client/ViewModels/TrustedNetworks/AddTrustedClientViewModel.cs

@@ -1,4 +1,4 @@
-using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.CodeAnalysis;
 using System.Reactive;
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
@@ -279,13 +279,13 @@ private async Task ValidateClient()
                 _publicKeysManager.Trust(TrustedPublicKey);
 
                 ShowSuccess = true;
-                await Task.Delay(TimeSpan.FromSeconds(3));
+                await DelayAsync(TimeSpan.FromSeconds(3));
                 ShowSuccess = false;
             }
             else
             {
                 ShowError = true;
-                await Task.Delay(TimeSpan.FromSeconds(3));
+                await DelayAsync(TimeSpan.FromSeconds(3));
                 ShowError = false;
             }
 
@@ -309,7 +309,7 @@ private async Task RejectClient()
             var task2 = _publicKeysTruster.OnPublicKeyValidationCanceled(PublicKeyCheckData!, TrustDataParameters);
 
             ShowError = true;
-            await Task.Delay(TimeSpan.FromSeconds(3));
+            await DelayAsync(TimeSpan.FromSeconds(3));
             ShowError = false;
 
             await Task.WhenAll(task, task2);
@@ -330,6 +330,8 @@ private async Task Cancel()
         await _publicKeysTruster.OnPublicKeyValidationCanceled(PublicKeyCheckData!, TrustDataParameters);
     }
 
+    protected virtual Task DelayAsync(TimeSpan delay) => Task.Delay(delay);
+
     private string[] BuildSafetyWords()
     {
         var safetyWordsComputer = new SafetyWordsComputer(SafetyWordsValues.AVAILABLE_WORDS);