Reading List Detail Overhaul + More Bugfixes and Polish (#3687)

Co-authored-by: Yongun Seong <yseong.p@gmail.com>

API/Controllers/LocaleController.cs

@@ -46,8 +46,8 @@ public class LocaleController : BaseApiController
         }
 
         var ret = _localizationService.GetLocales().Where(l => l.TranslationCompletion > 0f);
-        await _localeCacheProvider.SetAsync(CacheKey, ret, TimeSpan.FromDays(7));
+        await _localeCacheProvider.SetAsync(CacheKey, ret, TimeSpan.FromDays(1));
 
-        return Ok();
+        return Ok(ret);
     }
 }