install/upgrade refactoring to consolidate all use cases and implement IInstallable interface for modules, moved tenant creation to site management UI, fixed z-order issues in Blazor theme, enhanced JS Interop methods to support integrity and crossorigin

Oqtane.Server/Infrastructure/Interfaces/IDatabaseManager.cs

@@ -0,0 +1,12 @@
+using Oqtane.Models;
+using Oqtane.Shared;
+
+namespace Oqtane.Infrastructure
+{
+    public interface IDatabaseManager
+    {
+        bool IsInstalled();
+        Installation Install();
+        Installation Install(InstallConfig install);
+    }
+}