Add support for more NgModule metadata props in SandboxOfConfig about angular-playground

[FDIM]

I've made a PR that most likely fixes this issue - I'll verify if it does at work and update tomorrow (I don't see why it shouldn't).

Edit: I can confirm that it works

[jedrichards]

I'd really dig being able to define entryComponents in a sandbox (to sandbox modals made with @angular/cdk Overlay). For some reason when I add the needed entryComponents and declarations in the root playground.module.ts file instead it borks my actual main app build (I get component declared in multiple module errors). Why my main build is even looking in playground.module.ts I'm not sure, since no app code references or imports that file.

I'm pretty new to Angular >= 2, but will there be much work involved in adding entryComponents support to sandboxes? Could possibly take a look ...

[cdeturche]

Needed to check behavior with modals.

Thank you.