StrategyBase should throw when an inheritor returns a non-sensical state for cells

[mmmcaffeine]

It would be possible to detect a number of error conditions in the bool?[] returned by sub-classes, and throw an appropriate exception in these scenarios.

We should throw exceptions when:

• there are more filled cells than the hint calls for
• there are not enough filled or undetermined cells to fulfil the hint
• there are runs of cells that are longer than the hint calls for
• there are less runs of cells than the hint calls for, and not enough undetermined cells to fit the remaining runs
• there are more runs of cells than the hint calls for (taking into account some runs might get joined)