feat: add object access node

[seelengxd]

new steps

1. ObjectAccessNode - to extract field from dictionary
2. OutputStep

fixes

• removes assumption that all input sockets have something connecting to it

modification to original utils.py in json file:

1. generate_init_state is now a dictionary including the move

   def generate_init_state():
   state = [
       ["B"] * COL,
       ["B"] * COL,  # 2 black rows
       ["_"] * COL,
       ["_"] * COL,  # 2 empty rows
       ["W"] * COL,
       ["W"] * COL,  # 2 white rows
   ]
   return {"board": state, "move": "B"}

2. adds this function

   # makes a move effective on the board by modifying board state, or returning a new board with updated board state
   def state_change_modified(state, move, in_place=True):
   curr_board = state["board"]
   
   from_, to_ = move
   """Updates the board configuration by modifying existing values if in_place is set to True, or creating a new board with updated values if in_place is set to False"""
   board = curr_board
   if not in_place:
       board = copy.deepcopy(curr_board)
   if is_valid_move(board, from_, to_):
       board[from_[0]][from_[1]] = "_"
       board[to_[0]][to_[1]] = "B"
   
   state["board"] = curr_board
   state["move"] = "W" if state["move"] == "B" else "B"