Create NextJS pages router example for `sensitiveInfo` rule

[e-moran]

We want to add an example to ensure that this continues to work correctly in to the future. We also need to check that it works correctly if body parsing is disabled, and perhaps add readBody if it does not.

According to https://nextjs.org/docs/pages/building-your-application/routing/api-routes#request-helpers, it seems that you'll have a stream-like object if it is disabled.