title: JSON.stringify in response option of cy.route is not working
body: <p>I'm currently writing tests on Cypress for an application writen in react and using redux and redux-saga. For one of my tests, I'm trying to stub a request and returning a response that the code is expecting to be an 'stringified' array by JSON so it can be parsed later.</p>
  
  <p>I've tried to specify a response in the cy.route() command using JSON.stringify([desiredResponse]) but that is not working, response keeps being kind of parsed by Cypress or some other middleware before getting to the saga.</p>
  
  <p>I've also tried to intercept the response in the onResponse option but seems to me like that's being executed once the response was delivered (not sure about this, made a couple of vague tests only)</p>
  
  <pre><code>// This is how my cy.route() config looks like
  cy.route({
    method: 'POST',
    url: 'someUrl',
    response: JSON.stringify([myResponse]),
  });
  </code></pre>
  
  <p>And in my saga:</p>
  
  <pre><code>// I call the url via axios and immediately after I try to parse it 
  try {
    const parsed = JSON.parse(response.data);
  } catch (err) {
    const parsed = [];
  }
  </code></pre>
  
  <p>I would expect my response in the saga to be something like: "[myResponse]" but I got the raw array instead</p>