refactor(core): make Testability compatible with tree-shaking (#45657)

This commit refactors the `Testability`-related logic to extract the necessary providers into a separate array, so that it can later become it's own NgModule (or exposed as an array of providers) and be excluded from the new APIs by default.

PR Close #45657

goldens/public-api/core/index.md

@@ -1272,7 +1272,7 @@ export abstract class TemplateRef<C> {
 
 // @public
 export class Testability implements PublicTestability {
-    constructor(_ngZone: NgZone);
+    constructor(_ngZone: NgZone, registry: TestabilityRegistry, testabilityGetter: GetTestability);
     // @deprecated
     decreasePendingRequestCount(): number;
     findProviders(using: any, provider: string, exactMatch: boolean): any[];
@@ -1290,7 +1290,6 @@ export class Testability implements PublicTestability {
 
 // @public
 export class TestabilityRegistry {
-    constructor();
     findTestabilityInTree(elem: Node, findInAncestors?: boolean): Testability | null;
     getAllRootElements(): any[];
     getAllTestabilities(): Testability[];

goldens/size-tracking/aio-payloads.json

@@ -12,7 +12,7 @@
   "aio-local": {
     "uncompressed": {
       "runtime": 4343,
-      "main": 454248,
+      "main": 454794,
       "polyfills": 33980,
       "styles": 71714,
       "light-theme": 78213,

goldens/size-tracking/integration-payloads.json

@@ -2,7 +2,7 @@
   "cli-hello-world": {
     "uncompressed": {
       "runtime": 1083,
-      "main": 126738,
+      "main": 126542,
       "polyfills": 33824
     }
   },
@@ -19,7 +19,7 @@
   "cli-hello-world-ivy-compat": {
     "uncompressed": {
       "runtime": 1102,
-      "main": 133348,
+      "main": 133968,
       "polyfills": 33957
     }
   },
@@ -41,7 +41,7 @@
   "forms": {
     "uncompressed": {
       "runtime": 1063,
-      "main": 158922,
+      "main": 159280,
       "polyfills": 33804
     }
   },