[Spatial Partition] (Fix) Issue #2544: Can not run App.java & some logs are wrong (#2545)

* [Spatial Partition] (Fix) Issue #2544

- ConcurrentModificationException
- Wrong log
- Log using formatting anchor

* [Spatial Partition] (Change) Hashtable to Map, (Remove) unused variable BUBBLE

spatial-partition/src/main/java/com/iluwatar/spatialpartition/Point.java

@@ -25,7 +25,7 @@
 package com.iluwatar.spatialpartition;
 
 import java.util.Collection;
-import java.util.HashMap;
+import java.util.Map;
 
 /**
  * The abstract Point class which will be extended by any object in the field whose location has to
@@ -65,5 +65,5 @@ public abstract class Point<T> {
    * @param toCheck contains the objects which need to be checked
    * @param all     contains hashtable of all points on field at this time
    */
-  abstract void handleCollision(Collection<? extends Point> toCheck, HashMap<Integer, T> all);
+  abstract void handleCollision(Collection<? extends Point> toCheck, Map<Integer, T> all);
 }