fix: add remainingClaimBlocks to OfflinePlayerData

common/src/main/java/io/github/flemmli97/flan/player/OfflinePlayerData.java

@@ -83,6 +83,11 @@ public class OfflinePlayerData implements IPlayerData {
         return usedClaimsBlocks;
     }
 
+    @Override
+    public int remainingClaimBlocks() {
+        return this.getClaimBlocks() + this.getAdditionalClaims() - this.usedClaimBlocks();
+    }
+
     @Override
     public void setAdditionalClaims(int amount) {
         this.additionalClaimBlocks = amount;