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`

packages/core/test/linker/integration_spec.ts

@@ -1264,13 +1264,12 @@ function declareTests({useJit}: {useJit: boolean}) {
         TestBed.createComponent(SomeComponent);
 
         expect(noSelectorComponentFactory.selector).toBe('ng-component');
+
         expect(
             getDOM()
-                .nodeName(
-                    noSelectorComponentFactory.create(TestBed.get(Injector)).location.nativeElement)
+                .nodeName(noSelectorComponentFactory.create(Injector.NULL).location.nativeElement)
                 .toLowerCase())
             .toEqual('ng-component');
-
       });
     });