fix(ivy): platform module bootstrap does not resolve resources (#29083)

Currently with ViewEngine, if someone runs the platform's
`bootstrapModule` method in order to boostrap a module in
JIT mode, external component resources are properly resolved
*automatically*.

Currently with Ivy, the developer would need to manually call
`resolveComponentResources` in order to asynchronously fetch
the determined external component resources. In order to make
this backwards compatible with ViewEngine, and also since
platforms can already specify a `ResourceLoader` compiler
provider, we need to automatically resolve all external
component resources on module bootstrap.

--

Since the `ResourceLoader` is part of the `@angular/compiler`,
because ViewEngine performed the factory creation in the compiler,
we can't access the `ResourceLoader` token from within core.

In order to workaround this without introducing a breaking change,
we just proxy the `ResourceLoader` token to `core` through the
compiler facade. In the future, we should be able to move the
`ResourceLoader` to core when ViewEngine code no longer exists in
the `@angular/compiler`.

PR Close #29083

packages/compiler/src/compiler_facade_interface.ts

@@ -41,10 +41,15 @@ export interface CompilerFacade {
   createParseSourceSpan(kind: string, typeName: string, sourceUrl: string): ParseSourceSpan;
 
   R3ResolvedDependencyType: typeof R3ResolvedDependencyType;
+  ResourceLoader: {new (): ResourceLoader};
 }
 
 export interface CoreEnvironment { [name: string]: Function; }
 
+export type ResourceLoader = {
+  get(url: string): Promise<string>| string;
+};
+
 export type StringMap = {
   [key: string]: string;
 };

packages/compiler/src/jit_compiler_facade.ts

@@ -23,10 +23,12 @@ import {R3Reference} from './render3/util';
 import {R3DirectiveMetadata, R3QueryMetadata} from './render3/view/api';
 import {ParsedHostBindings, compileComponentFromMetadata, compileDirectiveFromMetadata, parseHostBindings, verifyHostBindings} from './render3/view/compiler';
 import {makeBindingParser, parseTemplate} from './render3/view/template';
+import {ResourceLoader} from './resource_loader';
 import {DomElementSchemaRegistry} from './schema/dom_element_schema_registry';
 
 export class CompilerFacadeImpl implements CompilerFacade {
   R3ResolvedDependencyType = R3ResolvedDependencyType as any;
+  ResourceLoader = ResourceLoader;
   private elementSchemaRegistry = new DomElementSchemaRegistry();
 
   constructor(private jitEvaluator = new JitEvaluator()) {}