fix: TKDPointTree Int32 overflow with large TPoints

Author: Torwent

Source/simba.container_kdpointtree.pas

@@ -235,7 +235,8 @@ function TKDPointTree.RawNearest(pt:TPoint; notEqual:Boolean=False): PNode;
   resNode:PNode;
   procedure __nearest(node:Integer; depth:UInt8=0);
   var
-    test,dist,delta:Integer;
+    dist: Int64;
+    test,delta:Integer;
     this:PNode;
   begin
     this := @self.data[node];