title: TFS: How to add more 'CheckIn' actions
body: <p>Out-of-the-box TFS provides ability to either "Associate" or "Resolve" bug/task during check-in action.</p>
  
  <p>I've added additional state "Implemented", created transition from "Active" to "Implemented", added into its "Action" value "Microsoft.VSTS.Actions.Checkin" and expect to have "Implemented" option in the list of "Check-in Action" on the "Pending changed => Work Items" panel.</p>
  
  <p>I've saved updated work item type, imported it into TFS, 'refresged' team explorer... but in "Check-in Action" list there are still only "Associate" and "Resolve".</p>
  
  <p>Please advise: how to add additional options into that list and implement switch of work item state.</p>
  
  <p>Any thoughts are welcome. Thanks!</p>