Modify get_board_visual function Change chess pieces expressed in alp…

[HyoungSooo]

Hello zhelyabuzhsky!

I am making a chess game using the stockfish engine in the terminal.
Changed the visual aspect of the chess board as it appears in the terminal.
We added a parameter to the function, which allows you to use both the alphabet version and the 2D character version.
with created test code and it will be passed

2d charactor version

+---+---+---+---+---+---+---+---+
| ♖ | ♘ | ♗ | ♕ | ♔ | ♗ | ♘ | ♖ | 8
+---+---+---+---+---+---+---+---+
| ♙ | ♙ | ♙ |   |   | ♙ | ♙ | ♙ | 7
+---+---+---+---+---+---+---+---+
|   |   |   |   | ♙ |   |   |   | 6
+---+---+---+---+---+---+---+---+
|   |   |   | ♙ |   |   |   |   | 5
+---+---+---+---+---+---+---+---+
|   |   |   | ♟ | ♟ |   |   |   | 4
+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |   | 3
+---+---+---+---+---+---+---+---+
| ♟ | ♟ | ♟ |   |   | ♟ | ♟ | ♟ | 2
+---+---+---+---+---+---+---+---+
| ♜ | ♞ | ♝ | ♛ | ♚ | ♝ | ♞ | ♜ | 1
+---+---+---+---+---+---+---+---+
  a   b   c   d   e   f   g   h