This adds the feature for `@ViewChild`/`@ViewChildren`/`@ContentChild`/`@ContentChildren` to define what to read from the queried element.
E.g. `@ViewChild(`someVar`, read: ViewContainerRef)` will locate the element with a variable `someVar` on it and return a `ViewContainerRef` for it.
Background: With this change, Angular knows exactly at which elements there will be `ViewConainerRef`s as the user has to ask explicitly of them. This simplifies codegen and will make converting Angular templates into server side templates simpler as well.
BREAKING CHANGE:
- `DynamicComponentLoader.loadIntoLocation` has been removed. Use `@ViewChild(‘myVar’, read: ViewContainerRef)` to get hold of a `ViewContainerRef` at an element with variable `myVar`.
- `DynamicComponentLoader.loadNextToLocation` now takes a `ViewContainerRef` instead of an `ElementRef`.
- `AppViewManager` is renamed into `ViewUtils` and is a mere private utility service.