feat(core): properly support inheritance

## Inheritance Semantics:

Decorators:
1) list the decorators of the class and its parents in the ancestor first order
2) only use the last decorator of each kind (e.g. @Component / ...)

Constructor parameters:
If a class inherits from a parent class and does not declare
a constructor, it inherits the parent class constructor,
and with it the parameter metadata of that parent class.

Lifecycle hooks:
Follow the normal class inheritance model,
i.e. lifecycle hooks of parent classes will be called
even if the method is not overwritten in the child class.

## Example

E.g. the following is a valid use of inheritance and it will
also inherit all metadata:

```
@Directive({selector: 'someDir'})
class ParentDirective {
  constructor(someDep: SomeDep) {}

  ngOnInit() {}
}

class ChildDirective extends ParentDirective {}
```

Closes #11606
Closes #12892

modules/@angular/facade/src/collection.ts

@@ -52,6 +52,15 @@ export class StringMapWrapper {
 export interface Predicate<T> { (value: T, index?: number, array?: T[]): boolean; }
 
 export class ListWrapper {
+  static findLast<T>(arr: T[], condition: (value: T) => boolean): T {
+    for (let i = arr.length - 1; i >= 0; i--) {
+      if (condition(arr[i])) {
+        return arr[i];
+      }
+    }
+    return null;
+  }
+
   static removeAll<T>(list: T[], items: T[]) {
     for (let i = 0; i < items.length; ++i) {
       const index = list.indexOf(items[i]);