refactor(compiler): split compiler and core (#18683)

After this, neither @angular/compiler nor @angular/comnpiler-cli depend
on @angular/core.

This add a duplication of some interfaces and enums which is stored
in @angular/compiler/src/core.ts

BREAKING CHANGE:
- `@angular/platform-server` now additionally depends on
  `@angular/platform-browser-dynamic` as a peer dependency.


PR Close #18683

packages/platform-browser-dynamic/testing/src/private_export_testing.ts

@@ -7,3 +7,4 @@
  */
 
 export {DOMTestComponentRenderer as ɵDOMTestComponentRenderer} from './dom_test_component_renderer';
+export {platformCoreDynamicTesting as ɵplatformCoreDynamicTesting} from './platform_core_dynamic_testing';