Add user manager page (#22)

Reviewed-on: #22

src/GameIdeas/Client/GameIdeas.BlazorApp/Pages/Users/Gateways/IUserGateway.cs

@@ -0,0 +1,13 @@
+using GameIdeas.BlazorApp.Pages.Users.Filters;
+using GameIdeas.Shared.Dto;
+
+namespace GameIdeas.BlazorApp.Pages.Users.Gateways;
+
+public interface IUserGateway
+{
+    Task<UserListDto> GetUsers(UserFilterParams filterParams, int currentPage);
+    Task<IEnumerable<RoleDto>> GetRoles();
+    Task<IdDto> CreateUser(UserDto user);
+    Task<IdDto> UpdateUser(UserDto user);
+    Task<IdDto> DeleteUser(string userId);
+}