Highlight Notes

[jlnordin]

This PR adds support for highlighting all notes that match a particular number when a cell is selected. This also includes a new setting to turn off this behavior if desired.

Highlighting note values is particularly important for more complex Sudoku games where figuring out what notes to remove is a large part of the game. This process can be greatly helped by visualizing the patterns the notes make.

Testing

• Verified selecting different cell values on each of the input methods highlights the correct notes.
• Verified selecting different cell values with note highlighting turned off.
• Verified selecting different cell values with no highlighting at all.

[ogarcia]

Merged! I see that you used SwitchPreference instead CheckBoxPreference in this new setting. What do you think about change all CheckBoxPreferences to SwitchPreferences?

[obar]

Thanks @jlnordin, I've thought how this feature would be helpful and you've done it!