Fix SearchForImages.md | incorrect node name in json request doc

Incorrect node name `SearchForImagesRequestBody` in documentation is causing `ASE-001` error on `SearchForImages` request

```js
{ 
   Status: 'error', 
   StatusList: [ { 
      Type: 'Error', 
      Code: 'ASE-001', 
      Message: 'Unknown error.'
   } ], 
   CoordinationId: '' 
}
```

should be `SearchForImages2RequestBody`