Artemis: Optimize Methods in Double Class for Enhanced Performance

[mike-turintech]

This pull request implements several optimizations in the Double class methods to improve performance and readability. Key changes include:

1. Optimized sumSquare Method: Simplified the logic by removing nested loops and directly calculating the sum of squares.
2. Refined sumTriangle Method: Adjusted the loop range and replaced nested loops with a direct calculation using the triangular number formula.
3. Improved countPairs Method: Enhanced efficiency by replacing nested loops with a single loop that tracks occurrences using an array, reducing time complexity from O(n^2) to O(n).
4. Enhanced countDuplicates Method: Limited loop iterations to the smaller length of input arrays and simplified equality checks.
5. Code Formatting: General cleanup for better readability and consistency.

These changes collectively enhance the performance of the methods while maintaining their original functionality.