fix(registration): Fix registration in standalone usage

Registration of a translation bundle in standalone application didn't work 
without initializing global `_oc_l10n_registry_*` objects.

Add global registry initialization in `register` function.

Signed-off-by: Grigorii Shartsev <grigorii.shartsev@nextcloud.com>

lib/registry.ts

@@ -36,6 +36,12 @@ export function registerAppTranslations(
 	translations: Translations,
 	pluralFunction: PluralFunction
 ) {
+	if (window._oc_l10n_registry_translations === undefined) {
+		window._oc_l10n_registry_translations = {}
+	}
+	if (window._oc_l10n_registry_plural_functions === undefined) {
+		window._oc_l10n_registry_plural_functions = {}
+	}
 	if (!hasAppTranslations(appId)) {
 		setAppTranslations(appId, translations, pluralFunction)
 	} else {
@@ -64,7 +70,7 @@ export function getAppTranslations(appId: string): AppTranslations {
 		typeof window._oc_l10n_registry_translations === 'undefined'
 		|| typeof window._oc_l10n_registry_plural_functions === 'undefined'
 	) {
-		console.warn('No OC L10N registry found')
+		console.warn(`No translation for ${appId} found`)
 		return {
 			translations: {},
 			pluralFunction: (number: number) => number,