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/Services/CustomReportProvider.cs

@@ -5,7 +5,16 @@ using EnvelopeGenerator.ReceiverUI.PredefinedReports;
 namespace EnvelopeGenerator.ReceiverUI.Services
 {
     public class CustomReportProvider : IReportProviderAsync {
+        private readonly InMemoryReportStorageWebExtension reportStorage;
+
+        public CustomReportProvider(InMemoryReportStorageWebExtension reportStorage) {
+            this.reportStorage = reportStorage;
+        }
+
         public Task<XtraReport> GetReportAsync(string id, ReportProviderContext context) {
+            if(reportStorage.TryGetReport(id, out var savedReport))
+                return Task.FromResult(savedReport);
+
             return Task.FromResult(ReportsFactory.GetReport(id));
         }
     }