Add Issuer and Subject to user list command (#3063)

I believe that it is possible to endup in the following situation :

- A user logs in using an authorized OIDC provider
- A vikunja user is created with the issuer & subject from the OIDC provider
- The same user logs in using another OIDC provider
- A 2nd vikunja user is created with a different issuer (possibly all other fields beside `created`, `updated` and `id` are equals)

I think it is important to be able to distinguish them in the `user list` command.

Reviewed-on: https://kolaente.dev/vikunja/vikunja/pulls/3063
Co-authored-by: jyte <marc88@free.fr>
Co-committed-by: jyte <marc88@free.fr>

pkg/cmd/user.go

@@ -151,6 +151,8 @@ var userListCmd = &cobra.Command{
 			"Username",
 			"Email",
 			"Status",
+			"Issuer",
+			"Subject",
 			"Created",
 			"Updated",
 		})
@@ -161,6 +163,8 @@ var userListCmd = &cobra.Command{
 				u.Username,
 				u.Email,
 				u.Status.String(),
+				u.Issuer,
+				u.Subject,
 				u.Created.Format(time.RFC3339),
 				u.Updated.Format(time.RFC3339),
 			})