working customer post, get and delete

AB.Services.Abstractions/ISupplierService.cs

@@ -0,0 +1,11 @@
+using AB.Contracts;
+
+namespace AB.Services.Abstractions;
+
+public interface ISupplierService
+{
+    Task<SupplierDto> CreateAsync(SupplierForCreationDto supplierForCreation);
+    Task DeleteAsync(Guid supplierId, CancellationToken cancellationToken);
+    Task<IEnumerable<SupplierDto>> GetAllAsync(CancellationToken cancellationToken);
+    Task<SupplierDto> GetSupplierByIdAsync(Guid supplierId, CancellationToken cancellationToken);
+}