Add structured multi-project storage

MauiProgram.cs

@@ -21,6 +21,7 @@ public static class MauiProgram
         builder.Services.AddSingleton<OfficialCadastreService>();
         builder.Services.AddSingleton<LocationSearchService>();
         builder.Services.AddSingleton<AzureMapsService>();
+        builder.Services.AddSingleton<ProjectStorageService>();
 
 #if DEBUG
         builder.Services.AddBlazorWebViewDeveloperTools();