Method to get the information of a link of a mailing.
https://api.wbsrvc.com/Mailing/GetLinkInfo/
POST
| user_key Required |
User Key of the user who initiates the call. Type: string |
| link_id Required |
ID of the link. Type: integer |
| client_id Optional |
Client ID of the client in which the mailing is located. Type: integer |