Refactor user ID handling in command handlers and update Protobuf package version to 0.0.124

src/FrontOffice.BFF.Application/Common/Interfaces/ICurrentUserService.cs

@@ -2,7 +2,7 @@ namespace FrontOffice.BFF.Application.Common.Interfaces;
 
 public interface ICurrentUserService
 {
-    string? UserId { get; }
+    long? UserId { get; }
     string? FirstName { get; }
     string? LastName { get; }
     string? MobileNumber { get; }