title: Using searchCriteria.creatorId in Azure DevOps git api does not work
body: <p>I'm trying to query our repo with git api to get all pull request created by a certain user:</p>
  <p><a href="https://tfs.XXXXX.org/tfs/DefaultCollection/Project/_apis/git/pullrequests?searchCriteria.creatorId=domain%5C%5CDEF" rel="nofollow noreferrer">https://tfs.XXXXX.org/tfs/DefaultCollection/Project/_apis/git/pullrequests?searchCriteria.creatorId=domain\\DEF</a></p>
  <p>But I'm still getting pull requests from other users as well:</p>
  <p>This is the JSON result:</p>
  <pre><code>&quot;value&quot;: [
      {
          .....
          &quot;createdBy&quot;: {
              &quot;displayName&quot;: &quot;ABC&quot;,
              ....
              &quot;uniqueName&quot;: &quot;domain\\ABC&quot;,
          },
          .....
          &quot;createdBy&quot;: {
              &quot;displayName&quot;: &quot;DEF&quot;,
              ....
              &quot;uniqueName&quot;: &quot;domain\\DEF&quot;,
          },
  </code></pre>
  <p>What am I doing wrong?</p>