Checkout should not give 404 when not added in storefront

Steps:

1. Go to Storefront (have products, payment, shipment completed)
2. Make sure in storefont repo change name of folder storefont/checkout to checkout2 or whatever else, you can even remove it so storefront take checkout from checkout repo not from this folder (It stills use checkout but with improvements!)
3. Buy something expensive!

Actual result:
You are getting 404 since checkout repo is not adapted to work without some improvments

Expected result:

Storefront work without checkout folder!