feat: create SUPPRESS_UNSAVED_CHANGES_WARNING token

#4444

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

@@ -1,3 +1,4 @@
 export * from './append-content.token';
 export * from './http-error.token';
 export * from './lazy-styles.token';
+export * from './suppress-unsaved-changes-warning.token';

npm/ng-packs/packages/theme-shared/src/lib/tokens/suppress-unsaved-changes-warning.token.ts

@@ -0,0 +1,5 @@
+import { InjectionToken } from '@angular/core';
+
+export const SUPPRESS_UNSAVED_CHANGES_WARNING = new InjectionToken<boolean>(
+  'SUPPRESS_UNSAVED_CHANGES_WARNING',
+);