Add FileName property to ReportRenderResult so that download name can…

… be determined from the result without having

src/Serenity.Net.Services/Reporting/IReportCallbackInterceptor.cs

@@ -0,0 +1,14 @@
+namespace Serenity.Reporting;
+
+/// <summary>
+/// Abstraction for a report callback interceptor that is called by ~/Serenity.Extensions/Report/Render.
+/// This is implemented by HtmlReportCallbackUrlInterceptor to implement impersonation and transient
+/// granting during report callbacks.
+/// </summary>
+public interface IReportCallbackInterceptor
+{
+    /// <summary>
+    /// Intercepts ReportController Render action callbacks.
+    /// </summary>
+    ReportRenderResult InterceptCallback(ReportRenderOptions options, Func<ReportRenderOptions, ReportRenderResult> action);
+}