Add Sudoku backtracking algorithm

[nyctophiliacme]

Is your feature request related to a problem? Please describe.
Yes, it is related to the Sudoku problem. Given the sudoku puzzle of a 9×9 2D array, the goal is to assign digits (from 1 to 9) to the empty cells so that every row, column, and subgrid of size 3×3 contains exactly one instance of the digits from 1 to 9.

Describe the solution you'd like
Assign a number to cell and recursively check whether if this assignment leads to a solution or not. If the assignment doesn’t lead to a solution, then try the next number for the current empty cell.

Describe alternatives you've considered
The simple approach, without backtracking is to generate all possible configurations of numbers from 1 to 9 to fill the empty cells. Then check if the solution is valid or not.

[siriak]

We already have that in Other/Sudoku.java, thanks!