Add JWT, OTP, and caching features

Upgraded projects to .NET 9.0 and added new projects `KBR.Cache`, `KBR.Shared`, and `KBR.Shared.Lite` to the solution. Introduced JWT authentication and OTP handling with new models, services, and configuration options. Updated database schema with new entities `Users` and `RefreshTokens`, and added migrations for schema changes. Implemented caching strategies using `AppDistributedCache` with support for in-memory, SQL Server, and Redis. Enhanced email handling with `MailHelpers` for domain replacement. Updated controllers, repositories, and configuration files to support new features.

Shared/KBR.Cache/Options/CacheOptions.cs

@@ -0,0 +1,9 @@
+namespace KBR.Cache.Options
+{
+    public class CacheOptions
+    {
+        public string Provider { get; set; } = null!;
+
+        public string? ConnectionString { get; set; }
+    }
+}