TurnitinOC: Add a save changes parameter to the viewer launch URL request

As a developer using a TCA integration, I want the ability to pass an updated score back to the end user. This is done via passing in the following parameter "save changes" into the CREATE viewer launch URL request to make reports "sticky". This works with the updated score webhook:

{
  "similarity": {
    "view_settings": {
      "save_changes": true
    }
  }
}