Autoreveal Tiles when Forced to Guess after Initial Move

[misterperson]

If the first tile revealed is shown to only have unknowns around it by the solver, the game should begin expanding outward from this initial tile until a mine or safe square is revealed.

Currently, it's very easy to abuse the guess mechanic to create long diagonal chains at the start of a board, making it hard for the algorithm to present challenging board states, even on the hardest difficulty.