Add failed embed for /listremind (#88)

Without this embed, if there are no reminders created by the user, the
bot will endlessly think because StringBuilder will be empty and normal
embed will not be shown.

locale/Messages.resx

@@ -591,4 +591,7 @@
   <data name="ReminderDeleted" xml:space="preserve">
         <value>Reminder deleted</value>
     </data>
+    <data name="NoRemindersFound" xml:space="preserve">
+        <value>You don't have any reminders created!</value>
+    </data>
 </root>

locale/Messages.ru.resx

@@ -591,4 +591,7 @@
     <data name="ReminderDeleted" xml:space="preserve">
         <value>Напоминание удалено</value>
     </data>
+    <data name="NoRemindersFound" xml:space="preserve">
+        <value>У вас нет созданных напоминаний!</value>
+    </data>
 </root>

locale/Messages.tt-ru.resx

@@ -591,4 +591,7 @@
     <data name="ReminderDeleted" xml:space="preserve">
         <value>напоминалка уничтожена</value>
     </data>
+    <data name="NoRemindersFound" xml:space="preserve">
+        <value>ты еще не крафтил напоминалки</value>
+    </data>
 </root>

src/Commands/RemindCommandGroup.cs

@@ -61,14 +61,29 @@ public class RemindCommandGroup : CommandGroup
             return Result.FromError(userResult);
         }
 
+        var currentUserResult = await _userApi.GetCurrentUserAsync(CancellationToken);
+        if (!currentUserResult.IsDefined(out var currentUser))
+        {
+            return Result.FromError(currentUserResult);
+        }
+
         var data = await _guildData.GetData(guildId, CancellationToken);
         Messages.Culture = GuildSettings.Language.Get(data.Settings);
 
-        return await ListRemindersAsync(data.GetOrCreateMemberData(userId), user, CancellationToken);
+        return await ListRemindersAsync(data.GetOrCreateMemberData(userId), user, currentUser, CancellationToken);
     }
 
-    private async Task<Result> ListRemindersAsync(MemberData data, IUser user, CancellationToken ct)
+    private async Task<Result> ListRemindersAsync(MemberData data, IUser user, IUser currentUser, CancellationToken ct)
     {
+        if (data.Reminders.Count == 0)
+        {
+            var failedEmbed = new EmbedBuilder().WithSmallTitle(Messages.NoRemindersFound, currentUser)
+                .WithColour(ColorsList.Red)
+                .Build();
+
+            return await _feedback.SendContextualEmbedResultAsync(failedEmbed, ct);
+        }
+
         var builder = new StringBuilder();
         for (var i = 0; i < data.Reminders.Count; i++)
         {

src/Messages.Designer.cs

@@ -995,5 +995,11 @@ namespace Boyfriend {
                 return ResourceManager.GetString("ReminderDeleted", resourceCulture);
             }
         }
+
+        internal static string NoRemindersFound {
+            get {
+                return ResourceManager.GetString("NoRemindersFound", resourceCulture);
+            }
+        }
     }
 }