Added average performance tiebreak by renaming performance

Performance is now equal to Player::getPerformance

src/Enums/Tiebreak.php

@@ -20,6 +20,7 @@ class Tiebreak extends Enum
     const Between = "Mutual Result";
     const Koya = "Koya";
     const Baumbach = "Most wins"; // Ref: https://en.wikipedia.org/wiki/Tie-breaking_in_Swiss-system_tournaments#Most_wins_(Baumbach) Please tell me why?
+    const AveragePerformance = "Average performance";
     const Performance = "Performance";
     const Aro = "Average Rating";
     const AroCut = "Average Rating Cut";

src/Tournament.php

@@ -317,9 +317,12 @@ class Tournament extends Tiebreaks
             case Tiebreak::Cumulative:
                 return $this->calculateCumulative($player);
                 break;
-            case Tiebreak::Performance:
+            case Tiebreak::AveragePerformance:
                 return $this->calculateAveragePerformance($player);
                 break;
+            case Tiebreak::Performance:
+                return $player->getPerformance($this->getPriorityElo());
+                break;
             default:
                 return null;
         }