Non-existent routes should respond with 404

[michaelbromley]

Describe the bug
Currently, when requesting a route that is not defined, the server will hang and not return any response.

To Reproduce
Steps to reproduce the behavior:

1. Start the Vendure server
2. In the browser request http://localhost/bad-route
3. Browser will hang, no response

Expected behavior
It should 404.

Environment (please complete the following information):

• @vendure/core version: 0.4.0
• Nodejs version: 12.4.0
• Database (mysql/postgres etc): any

[Szbuli]

This issue still happens to 401. For example if you create a custom rest endpoint, not sure about built in routes.

[Szbuli]

The error happened when i added an authguard to the controller endpoint, but not added the authguard to nestjs (not set passportmodule as an import, and not set the strategy as a provider)

[Szbuli]

If i throw a Forbidden error in a rest controller. It will not return 403 to the client, it will hang