fix(core): Fix error messages containing colon char

Fixes #2153.This commit disables the i18next namespace feature, since we do not make use of it, and
it causes any user error messages containing a colon to break when returned via the API.

packages/core/src/i18n/i18n.service.ts

@@ -54,6 +54,7 @@ export class I18nService implements OnModuleInit {
             .use(Backend as any)
             .use(ICU as any)
             .init({
+                nsSeparator: false,
                 preload: ['en', 'de', 'ru', 'uk'],
                 fallbackLng: 'en',
                 detection: {