add translation keys (#246)

* Fix i18n tsc issue

"t" can return null by default.
This was already disabled in the config, but it had no effect on tsc.

* Fix translation in "DefaultNavBar"

key was missing and since this is a constant the translation wouldn't update in case the language got changed after first load.

* Enable typing for i18n translation keys

* Add translation keys

src/screens/SearchAll.tsx

@@ -19,6 +19,7 @@ import client from 'util/client';
 import { langCodeToName, langSortCmp, sourceDefualtLangs, sourceForcedDefaultLangs } from 'util/language';
 import useLocalStorage from 'util/useLocalStorage';
 import { ISource } from 'typings';
+import { useTranslation } from 'react-i18next';
 
 function sourceToLangList(sources: ISource[]) {
     const result: string[] = [];
@@ -34,6 +35,8 @@ function sourceToLangList(sources: ISource[]) {
 }
 
 const SearchAll: React.FC = () => {
+    const { t } = useTranslation();
+
     const [query] = useQueryParam('query', StringParam);
     const { setTitle, setAction } = useContext(NavbarContext);
     const [triggerUpdate, setTriggerUpdate] = useState<number>(2);
@@ -53,7 +56,7 @@ const SearchAll: React.FC = () => {
     const limit = new PQueue({ concurrency: 5 });
 
     useEffect(() => {
-        setTitle('Global Search');
+        setTitle(t('search.title.global_search'));
         setAction(<AppbarSearch />);
     }, []);
 
@@ -146,7 +149,7 @@ const SearchAll: React.FC = () => {
     }, []);
 
     useEffect(() => {
-        setTitle('Sources');
+        setTitle(t('source.title'));
         setAction(
             <>
                 <AppbarSearch autoOpen />
@@ -210,7 +213,7 @@ const SearchAll: React.FC = () => {
                                 setLastPageNum={setLastPageNum}
                                 horizontal
                                 noFaces
-                                message={fetched[id] ? 'No manga was found!' : undefined}
+                                message={fetched[id] ? t('manga.error.label.no_mangas_found') : undefined}
                                 inLibraryIndicator
                             />
                         </>