feat: Implement user permission checks and manual payment functionalities

- Added CheckUserPermissionQuery and CheckUserPermissionQueryHandler for permission validation.
- Introduced GetUserRolesQuery and GetUserRolesQueryHandler to retrieve user roles.
- Created IPermissionService interface and its implementation in PermissionService.
- Defined permission and role constants in PermissionDefinitions.
- Developed SetDefaultVatPercentageCommand and its handler for VAT configuration.
- Implemented GetCurrentVatPercentageQuery and handler to fetch current VAT settings.
- Added manual payment commands: CreateManualPayment, ApproveManualPayment, and RejectManualPayment with respective handlers and validators.
- Created GetManualPaymentsQuery and handler for retrieving manual payment records.
- Integrated gRPC services for manual payments with appropriate permission checks.
- Established Protobuf definitions for manual payment operations and metadata.

src/BackOffice.BFF.Application/Common/Interfaces/IApplicationContractContext.cs

@@ -61,5 +61,8 @@ public interface IApplicationContractContext
     // Public Messages
     PublicMessageContract.PublicMessageContractClient PublicMessages { get; }
 
+    // Manual Payments (Admin) - CMS gRPC
+    CMSMicroservice.Protobuf.Protos.ManualPayment.ManualPaymentContract.ManualPaymentContractClient ManualPayments { get; }
+
     #endregion
 }

src/BackOffice.BFF.Application/Common/Interfaces/IPermissionService.cs

@@ -0,0 +1,13 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace BackOffice.BFF.Application.Common.Interfaces;
+
+public interface IPermissionService
+{
+    Task<IReadOnlyList<string>> GetUserRolesAsync(CancellationToken cancellationToken);
+
+    Task<bool> HasPermissionAsync(string permission, CancellationToken cancellationToken);
+}
+