chore(hs): rename event display name 'Heykel Savasi' -> 'TvT Event' (strings only)

Display strings/messages/designations changed everywhere (Name, entrance
messages, NPC designation, HUD title). Code identifiers/namespaces/commands
unchanged. DB rows updated separately.

src/Persistence/Initialization/VersionSeasonSix/NpcInitialization.cs

@@ -769,7 +769,7 @@ internal partial class NpcInitialization : Version095d.NpcInitialization
         {
             var def = this.Context.CreateNew<MonsterDefinition>();
             def.Number = 560;
-            def.Designation = "Heykel Savasi Gorevlisi";
+            def.Designation = "TvT Event Gorevlisi";
             def.NpcWindow = NpcWindow.Undefined; // routed via IPlayerTalkToNpcPlugIn in a later task
             def.ObjectKind = NpcObjectKind.PassiveNpc;
             this.GameConfiguration.Monsters.Add(def);