Multi-threaded endgame tables

[oggy22]

Make use of multithreading, possibly std::future and related classes.

The Dependent tables should be created each in separate tasks. All tasks should be waited for to create the current table.

This depends on #24

[oggy22]

A very nice starting example using std::future and std::async:

#include <iostream>
#include <future>

// Function to calculate Fibonacci number
int fibonacci(int n) {
    if (n <= 1) return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
}

int main() {
    // Launch asynchronous task
    std::future<int> result = std::async(std::launch::async, fibonacci, 46);

    // Do some other work while waiting for the result
    std::cout << "Calculating Fibonacci(10) asynchronously..." << std::endl;

    // Get the result from the future
    int fib10 = result.get();

    std::cout << "Fibonacci(10) = " << fib10 << std::endl;

    return 0;
}