Add in-memory report storage and async report handling

Introduced `InMemoryReportStorageWebExtension` to manage
reports in memory, enabling dynamic report storage and
retrieval. Updated `ReportViewer.razor` to conditionally
render the `DxReportViewer` component and initialize
reports asynchronously.

Configured dependency injection in `Program.cs` to register
`InMemoryReportStorageWebExtension` as a singleton and
integrated it with `CustomReportProvider`. Registered
`EnvelopeGenerator.ReceiverUI.PredefinedReports.Report` as
a trusted class for deserialization.

Enhanced `CustomReportProvider` to fetch reports from
memory or generate them dynamically using `ReportsFactory`.
Added necessary `using` directives and ensured proper
report lifecycle management.

EnvelopeGenerator.ReceiverUI/Pages/ReportViewer.razor

@@ -1,12 +1,24 @@
 @page "/reportviewer/"
 @using DevExpress.XtraReports.UI;
+@using EnvelopeGenerator.ReceiverUI.Services;
+@inject InMemoryReportStorageWebExtension ReportStorage
 
 <link href="_content/DevExpress.Blazor.Themes/blazing-berry.bs5.min.css" rel="stylesheet" />
 <link href="_content/DevExpress.Blazor.Reporting.Viewer/css/dx-blazor-reporting-components.bs5.css" rel="stylesheet" />
 
-<DxReportViewer @ref="reportViewer" Report="Report" RootCssClasses="w-100 h-100" />
+@if(Report is not null) {
+    <DxReportViewer @ref="reportViewer" Report="Report" RootCssClasses="w-100 h-100" />
+}
 
 @code {
     DxReportViewer reportViewer;
-    XtraReport Report = new PredefinedReports.Report();
+    XtraReport? Report;
+
+    protected override async Task OnInitializedAsync() {
+        Report = ReportStorage.TryGetReport("LargeDatasetReport", out var savedReport)
+            ? savedReport
+            : PredefinedReports.ReportsFactory.GetReport("LargeDatasetReport");
+
+        await Task.CompletedTask;
+    }
 }