fix: element injector vs module injector (#15044)

fixes #12869
fixes #12889
fixes #13885
fixes #13870

Before this change there was a single injector tree.
Now we have 2 injector trees, one for the modules and one for the components.
This fixes lazy loading modules.

See the design docs for details:
https://docs.google.com/document/d/1OEUIwc-s69l1o97K0wBd_-Lth5BBxir1KuCRWklTlI4

BREAKING CHANGES

`ComponentFactory.create()` takes an extra optional `NgModuleRef` parameter.
No change should be required in user code as the correct module will be used
when none is provided

DEPRECATIONS

The following methods were used internally and are no more required:
- `RouterOutlet.locationFactoryResolver`
- `RouterOutlet.locationInjector`

modules/benchmarks/src/tree/ng2_next/tree.ts

@@ -7,7 +7,7 @@
  */
 
 import {NgIf} from '@angular/common';
-import {ComponentFactory, ComponentRef, Injector, RendererFactory2, RootRenderer, Sanitizer, TemplateRef, ViewContainerRef} from '@angular/core';
+import {ComponentFactory, ComponentFactoryResolver, ComponentRef, Injector, NgModuleRef, RendererFactory2, RootRenderer, Sanitizer, TemplateRef, ViewContainerRef} from '@angular/core';
 import {ArgumentType, BindingType, NodeFlags, ViewDefinition, ViewFlags, anchorDef, createComponentFactory, directiveDef, elementDef, initServicesIfNeeded, textDef, viewDef} from '@angular/core/src/view/index';
 import {DomRendererFactory2} from '@angular/platform-browser/src/dom/dom_renderer';
 import {DomSanitizerImpl, SafeStyle} from '@angular/platform-browser/src/security/dom_sanitization_service';
@@ -84,7 +84,7 @@ function TreeComponent_0(): ViewDefinition {
       });
 }
 
-export class AppModule implements Injector {
+export class AppModule implements Injector, NgModuleRef<any> {
   private sanitizer: DomSanitizerImpl;
   private componentFactory: ComponentFactory<TreeComponent>;
   private renderer2: RendererFactory2;
@@ -108,12 +108,22 @@ export class AppModule implements Injector {
         return this.sanitizer;
       case RootRenderer:
         return null;
+      case NgModuleRef:
+        return this;
     }
     return Injector.NULL.get(token, notFoundValue);
   }
 
   bootstrap() {
-    this.componentRef = this.componentFactory.create(this, [], this.componentFactory.selector);
+    this.componentRef =
+        this.componentFactory.create(Injector.NULL, [], this.componentFactory.selector, this);
   }
+
   tick() { this.componentRef.changeDetectorRef.detectChanges(); }
+
+  get injector() { return this; }
+  get componentFactoryResolver(): ComponentFactoryResolver { return null; }
+  get instance() { return this; }
+  destroy() {}
+  onDestroy(callback: () => void) {}
 }