Use PVPDificulty.dbc for bg/arena bracket selection (levels and difficulty)

src/game/DBCStructure.h

@@ -1141,6 +1141,19 @@ struct MovieEntry
     //uint32      unk2;                                     // 2 always 100
 };
 
+struct PvPDifficultyEntry
+{
+    //uint32      id;                                       // 0        m_ID
+    uint32      mapId;                                      // 1  
+    uint32      bracketId;                                  // 2 
+    uint32      minLevel;                                   // 3
+    uint32      maxLevel;                                   // 4
+    uint32      difficulty;                                 // 5
+
+    // helpers
+    BattleGroundBracketId GetBracketId() const { return BattleGroundBracketId(bracketId); }
+};
+
 struct QuestSortEntry
 {
     uint32      id;                                         // 0        m_ID