Artemis: Refactor: Improve efficiency of SingleForLoop methods

[mike-turintech]

Refactors the SingleForLoop class to improve the efficiency of its methods:

• sum_range: Replaced the for loop and list creation with a direct calculation using the formula n * (n - 1) // 2. This eliminates the need for a loop and list storage, resulting in O(1) time complexity.
• max_list: Replaced the for loop with the max() function. Includes a conditional to return 0 if the input list is empty. This utilizes Python's built-in function for finding the maximum value, which is generally more efficient.
• sum_modulus: Replaced the list and sum operation with a single loop that steps by m and sums the values, removing the unnecessary list creation and sum call.