Refactor DTOs, add Blazor WASM frontend, enable CORS

- Split `CatalogDto` into `CatalogReadDto` and `CatalogWriteDto` for clear separation of read/write operations in both backend and frontend.
- Updated API controllers, services, and AutoMapper profiles to use new DTOs; ensured audit fields are set in service layer.
- Enabled CORS in the API project to support Blazor WASM frontend.
- Added new Blazor WebAssembly project (`DbFirst.BlazorWasm`) with catalog management UI, API client, Bootstrap v5.1.0 styling, and configuration-driven API base URL.
- Included `bootstrap.min.css` and its source map for frontend styling and easier debugging.
- Updated solution file to include new project and support multiple build configurations.
- Result: improved API design, clean DTO separation, and a modern interactive frontend for catalog management.

DbFirst.BlazorWasm/Layout/NavMenu.razor

@@ -0,0 +1,34 @@
+<div class="top-row ps-3 navbar navbar-dark">
+    <div class="container-fluid">
+        <a class="navbar-brand" href="">DbFirst.BlazorWasm</a>
+        <button title="Navigation menu" class="navbar-toggler" @onclick="ToggleNavMenu">
+            <span class="navbar-toggler-icon"></span>
+        </button>
+    </div>
+</div>
+
+<div class="@NavMenuCssClass nav-scrollable" @onclick="ToggleNavMenu">
+    <nav class="flex-column">
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="" Match="NavLinkMatch.All">
+                <span class="bi bi-house-door-fill-nav-menu" aria-hidden="true"></span> Home
+            </NavLink>
+        </div>
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="catalogs">
+                <span class="bi bi-collection-nav-menu" aria-hidden="true"></span> Catalogs
+            </NavLink>
+        </div>
+    </nav>
+</div>
+
+@code {
+    private bool collapseNavMenu = true;
+
+    private string? NavMenuCssClass => collapseNavMenu ? "collapse" : null;
+
+    private void ToggleNavMenu()
+    {
+        collapseNavMenu = !collapseNavMenu;
+    }
+}