Change Array With Allowed Moves For Chess Piece

Change the data in the array with all of the moves for a chess piece,
in Chess Board, from being an another array of the location to a chess
piece object, for that cell. Because it will have move information
about the cell then just the location. Such as what type of chess piece
is on that cell, as this may be important later on.
Change Unit Testing Messages

Because in order to tell which test the message belongs to it should be
a little bit more descriptive. Also, add more asserts to the
GetAllowMovement unit tests in order to make sure that the cell is the
current one.