Refactored the `CommonEngine` API import path to remove Node.js dependencies from the `@angular/ssr` main entry-point.
BREAKING CHANGE:
The `CommonEngine` API now needs to be imported from `@angular/ssr/node`.
**Before**
```ts
import { CommonEngine } from '@angular/ssr';
```
**After**
```ts
import { CommonEngine } from '@angular/ssr/node';
```
