cli: support catch all routes (i.e. to a custom 404 page)

Steps to Reproduce

1. ng add @scullyio/init
2. npm i --save-dev fs-extra
3. ng build
4. npm run scully

Error

Cleaned up /Users/splaktar/Git/.../dist/static/ folder.
started servers in background
Invalid content-type.
Expected application/json but received text/html; charset=UTF-8
<repeated about 30 times>
Invalid content-type.
Expected application/json but received text/html; charset=UTF-8
Could not connect to server

The debugger indicates that this is caused by the following line https://github.com/scullyio/scully/blob/eba6fba6a5df182137fdb7b434893162bc962dc3/scully/utils/waitForServerToBeAvailable.ts#L13

That URL (http://localhost:1864/_pong) seems to be returning my Angular app (in a broken state) rather than some JSON content.

Root Cause

A route like {path: '**', component: PageNotFoundComponent} breaks the ability to run Scully. Removing it works around the problem, but breaks the app’s custom 404 page.

[SanderElias]

@Splaktar Yes, a partial fix might be in a bit earlier, but that one closed it completely.

[Hypercubed]

@SanderElias Are you able to share your PR? I’d like to test it if I can.