Add ForceToUseFakeDocument option for document loading

Introduced a new `ForceToUseFakeDocument` property in `ApiOptions` to control whether the application uses a fake document for testing or bypasses certain conditions for document loading. Updated `ReportViewer.razor` to respect this configuration, including changes to conditional rendering logic and dependency injection for `IOptions<ApiOptions>`.

Removed test code that forced `EnvelopeKey` to `null` during initialization. Updated `appsettings.json` to include the new `ForceToUseFakeDocument` property with a default value of `true`. Added necessary `using` directives and dependencies for the updated functionality.

EnvelopeGenerator.ReceiverUI/Options/ApiOptions.cs

@@ -5,4 +5,6 @@ public class ApiOptions
     public const string SectionName = "Api";
 
     public string BaseUrl { get; set; } = string.Empty;
+
+    public bool ForceToUseFakeDocument { get; set; } = false;
 }