Add IPolicyService registration in ServiceExtensions

This commit introduces a new service registration for the
IPolicyService interface in the ServiceExtensions.cs file,
implemented by the PolicyService class. This enhancement
improves the dependency injection setup, allowing
IPolicyService to be injected throughout the application.

Author: calin-lupas_dsamcaps

src/DevExcelerateApi/Core/Extensions/ServiceExtensions.cs

@@ -97,6 +97,7 @@ internal static IServiceCollection AddAppServices(this IServiceCollection servic
             services.AddSingleton<IRepositoryService, RepositoryService>();
             services.AddSingleton<ITeamService, TeamService>();
             services.AddSingleton<IIssueService, IssueService>();
+            services.AddSingleton<IPolicyService, PolicyService>();
 
             services.AddMemoryCache();
             services.AddSingleton<ICacheService, CacheService>();