Time for action – updating GameBoard to support animated pieces

1. In the declarations section of the GameBoard class, add three Dictionaries, shown as follows:

   Public FallingPieces As Dictionary(Of String, FallingPiece) = 
       New Dictionary(Of String, FallingPiece)
   Public RotatingPieces As Dictionary(Of String, RotatingPiece) = 
       New Dictionary(Of String, RotatingPiece)
   Public FadingPieces As Dictionary(Of String, FadingPiece) = 
       New Dictionary(Of String, FadingPiece)

2. Add methods to the GameBoard class to create new falling piece entries in the Dictionaries:

   Public Sub AddFallingPiece(x As Integer, y As Integer,
                              type As String, verticalOffset As Integer)
       FallingPieces.Add(
           x.ToString() + "_" + y.ToString(),
           New FallingPiece(type, verticalOffset))
   End Sub
   
   Public Sub AddRotatingPiece(x As Integer, y As Integer,
                               type As String, clockwise As Boolean)
       RotatingPieces.Add(
           x.ToString() + "_" + y.ToString...