feat(templates): improve SignalR method invoke in bit Boilerplate project template #11066 (#11067)

Author: ysmoradi

src/Templates/Boilerplate/Bit.Boilerplate/src/Server/Boilerplate.Server.Api/Controllers/Diagnostics/DiagnosticsController.cs

@@ -58,7 +58,11 @@ public async Task<string> PerformDiagnostics([FromQuery] string? signalRConnecti
         //#if (signalR == true)
         if (string.IsNullOrEmpty(signalRConnectionId) is false)
         {
-            await appHubContext.Clients.Client(signalRConnectionId).SendAsync(SignalREvents.SHOW_MESSAGE, $"Open terms page. {DateTimeOffset.Now:HH:mm:ss}", new { pageUrl = Urls.TermsPage, action = "testAction" }, cancellationToken);
+            var success = await appHubContext.Clients.Client(signalRConnectionId).InvokeAsync<bool>(SignalREvents.SHOW_MESSAGE, $"Open terms page. {DateTimeOffset.Now:HH:mm:ss}", new { pageUrl = Urls.TermsPage, action = "testAction" }, cancellationToken);
+            if (success is false) // Client would return false if it's unable to show the message with custom action.
+            {
+                await appHubContext.Clients.Client(signalRConnectionId).SendAsync(SignalREvents.SHOW_MESSAGE, $"Simple message. {DateTimeOffset.Now:HH:mm:ss}", null, cancellationToken);
+            }
         }
         //#endif