Add generic scoped request interfaces for MediatR support

Introduced IScopedRequestBase<TScope>, IScopedRequest<TScope>, and IScopedRequest<TScope, TResponse> interfaces to enable requests with scope information. These interfaces extend MediatR's IRequest types and enforce non-nullable scope types for improved request handling.

src/ReC.Application/Common/Interfaces/IScopedRequest.cs

@@ -0,0 +1,16 @@
+using MediatR;
+
+namespace ReC.Application.Common.Interfaces;
+
+public interface IScopedRequestBase<TScope> where TScope : notnull
+{
+    public TScope Scope { get; }
+}
+
+public interface IScopedRequest<TScope> : IRequest, IScopedRequestBase<TScope> where TScope : notnull
+{
+}
+
+public interface IScopedRequest<TScope, out TResponse> : IRequest<TResponse>, IScopedRequestBase<TScope> where TScope : notnull
+{
+}