refactor(ivy): move ngcc into a higher level folder (#29092)

PR Close #29092

packages/compiler-cli/ngcc/index.ts

@@ -0,0 +1,9 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+export {mainNgcc} from './src/main';