[PM-6511] New i18n for angular (#8122)

* Use state provider to store preferred language

* migrate preferred language

* Use new i18n provider to get LOCAL_ID

* Fix preloaded english i18n

This is a mock service that forces english translations, it doesn't need the i18n interface that allows changing of locales.

* PR improvements

* Fixup merge

libs/common/src/platform/abstractions/i18n.service.ts

@@ -4,4 +4,5 @@ import { TranslationService } from "./translation.service";
 
 export abstract class I18nService extends TranslationService {
   locale$: Observable<string>;
+  abstract setLocale(locale: string): Promise<void>;
 }