better message when people import fake built-ins?

[ryanflorence]

If you npm add crypto you get a build error no matter what:

> remix build

Building Remix app in production mode...
 > node_modules/@remix-run/node/sessions/fileStorage.js:6:21: error: Could not resolve "crypto" (use "platform: 'node'" when building for node)
    6 │ var crypto = require('crypto');
      ╵                      ~~~~~~~~

 > node_modules/cookie-signature/index.js:5:21: error: Could not resolve "crypto" (use "platform: 'node'" when building for node)
    5 │ var crypto = require('crypto');

I'm not sure why our compiler blows up on this (haven't dug in yet) but I know we look at the app deps and ignore built-ins, but maybe we ought to just not allow using any node modules w/ the same name as a built-in node module?