getCapturablePieces
Gets a list of capturable pieces in a specified direction from the given piece. A piece is considered capturable if it is of the opposite type and is followed by a piece of the same type as myPiece in the specified direction.
Return
A list of coordinates of capturable pieces in the specified direction.
Parameters
board
The current state of the board.
myPiece
The piece being placed on the board.
direction
The direction to check in (should be one of the 8 possible directions).
Throws
if the position is out of bounds