Add Highest Response Ratio Next(HRRN) Scheduling Algorithm

[harshitrajput2802]

Description of Change

Added an implementation of the Highest Response Ratio Next (HRRN) CPU scheduling algorithm, a non-preemptive scheduling technique that dynamically selects the ready process with the highest response ratio.

This implementation:

Selects processes based on the response ratio (waiting time + burst time) / burst time.
Recomputes response ratios at every scheduling decision, ensuring correct HRRN behavior.
Resolves ties deterministically using arrival time and process ID.
Includes an independent reference implementation for correctness verification.
Adds regression tests and randomized self-tests to validate the implementation against the reference scheduler.
Provides comprehensive Doxygen documentation and follows the project's coding conventions, including namespace organization and self-contained examples.

Checklist

• Added description of change
• Added file name matches File name guidelines
• Added tests and example, test must pass
• Added documentation so that the program is self-explanatory and educational
• Relevant documentation/comments is changed or added
• PR title follows semantic commit guidelines
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I acknowledge that all my contributions will be made under the project's license.

Notes: Implemented the Highest Response Ratio Next (HRRN) CPU scheduling algorithm with an independent reference implementation, regression tests, randomized validation, and comprehensive Doxygen documentation.