style: remove user interaction from fibonacci_matrix_exponentiation

[Hxrshthetic]

Description of Change

This PR refactors the fibonacci_matrix_exponentiation implementation by removing direct user interaction (cin/cout) from the core algorithm.

The implementation is updated to follow repository contribution guidelines by separating logic from input/output operations. The algorithm is now modular, accepts input via function parameters, and returns the computed result instead of printing it.

Checklist

• Added description of change
• Added file name matches File name guidelines
• 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: Refactored to remove I/O and align with contribution guidelines (Related to #2456)>