Makes validateWith async and a new validateWithSync synchronous

[cannikin]

Right now the validateWith() function doesn't work with functions that return promises, it blows up the API server. This PR updates the function to, by default, work with promises, and creates a new validateWithSync() which duplicates the old behavior of working with non-async functions only. The naming convention follows those of other React packages like fs.

Unfortunately, because it changes how the default function works, this is a backwards incompatible change and will need to be released in a major version. Whenever 5.0 is ready!

Todo:

• Docs
• Tests

[replay-io]

16 replays were recorded for 8ebe600.

0 Failed

16 Passed

requireAuth graphql checks

    ```
    locator.waitFor: Target closed
    =========================== logs ===========================
    waiting for locator('.rw-form-error-title').locator('text=You don\'t have permission to do that') to be visible
    ============================================================
    ```
  </ol>
</details>
<li><a href=https://app.replay.io/recording/94c3f9f3-4501-4028-a922-410f04b1e597>useAuth hook, auth redirects checks</a></li>
<li><a href=https://app.replay.io/recording/40a17cf3-7dc8-4246-8561-160d77aa244b>Check that a specific blog post is prerendered</a></li>
<li><a href=https://app.replay.io/recording/bfa749ae-3306-41df-b2a0-c8ae5aaa9d9e>Check that about is prerendered</a></li>
<li><a href=https://app.replay.io/recording/2e08f996-4533-478f-8924-32d29c4ef917>Check that homepage is prerendered</a></li>
<li><a href=https://app.replay.io/recording/23528ef4-5353-457f-b493-6cc371827eaf>Check that meta-tags are rendering the correct dynamic data</a></li>
<li><a href=https://app.replay.io/recording/b4eef66e-3dcf-4b55-908f-fcffabed411a>Check that you can navigate from home page to specific blog post</a></li>
<li><a href=https://app.replay.io/recording/855a0d21-28e8-492d-93c9-2b0125bac535>Waterfall prerendering (nested cells)</a></li>
<li><a href=https://app.replay.io/recording/1c853b24-e6e6-430e-bbbb-b2eee7578ff7>RBAC: Admin user should be able to delete contacts</a></li>
<li><a href=https://app.replay.io/recording/93ed2b0d-977c-4378-beaa-be0637c4f563>RBAC: Should not be able to delete contact as non-admin user</a></li>
<li><a href=https://app.replay.io/recording/850f2293-b0f7-4e95-9fe6-fb1d84436409>Smoke test with dev server</a></li>
<li><a href=https://app.replay.io/recording/9fb44b84-009b-4ebb-8bde-1dbdda8d65fa>Smoke test with rw serve</a></li>
<li><a href=https://app.replay.io/recording/1d96f89d-5572-47aa-a3a7-6f6524602a0a>Loads Cell mocks when Cell is nested in another story</a></li>
<li><a href=https://app.replay.io/recording/a4f82340-de50-4de9-9068-a99c9c7c3acc>Loads Cell Stories</a></li>
<li><a href=https://app.replay.io/recording/1fc5e950-2057-4f6e-98ff-63569d2141a9>Loads MDX Stories</a></li>
<li><a href=https://app.replay.io/recording/e6a6331e-569d-4a93-9456-fbaefb286c6a>Mocks current user, and updates UI while dev server is running</a></li>

View test run on Replay ↗︎

[jtoar]

@cannikin I think the codemod just needs to change all instances of validateWith to validateWithSync right?

[cannikin]

Yep that should be it!

[cannikin]

@jtoar Looks like this is good to go, feel free to merge whenever you're ready!