Refactor JumpablePathfinderStrategy for height calculation

The "JumpablePathfinderStrategy" class has been revised to include downward jumps in its calculations. A new private method "isJumpingDown" is introduced, which is used to calculate the height difference whether the entity is jumping upwards or downwards. Consequently, this increases the accuracy of the entity jumping mechanism in the game.

pathetic-api/src/main/java/org/patheloper/api/pathing/strategy/strategies/JumpablePathfinderStrategy.java

@@ -48,8 +48,21 @@ public boolean isValid(@NonNull PathValidationContext pathValidationContext) {
       return true;
     }
 
-    if ((position.getBlockY() - lastValidPosition.getBlockY()) > jumpHeight) return false;
+    int heightDiff = position.getBlockY() - lastValidPosition.getBlockY();
+    if (isJumpingDown(position, lastValidPosition)) {
+      heightDiff *= -1;
+    }
+
+    if (heightDiff > jumpHeight) {
+      return false;
+    }
 
     return startBlock.isPassable() && position.distance(lastValidPosition) <= maxJumpDistance;
   }
+
+  private boolean isJumpingDown(PathPosition position, PathPosition lastValidPosition) {
+    return position.getBlockX() == lastValidPosition.getBlockX()
+        && position.getBlockZ() == lastValidPosition.getBlockZ()
+        && position.getBlockY() < lastValidPosition.getBlockY();
+  }
 }