feat: add a lazy styles token

npm/ng-packs/packages/theme-shared/src/lib/tokens/index.ts

@@ -1,2 +1,3 @@
 export * from './append-content.token';
 export * from './http-error.token';
+export * from './lazy-styles.token';

npm/ng-packs/packages/theme-shared/src/lib/tokens/lazy-styles.token.ts

@@ -0,0 +1,3 @@
+import { InjectionToken } from '@angular/core';
+
+export const LAZY_STYLES = new InjectionToken<string[]>('LAZY_STYLES');