Description of Change

This PR adds a palindrome number checker as requested in issue #3046.

• Added new file: math/palindrome_number.cpp
• Implemented is_palindrome() function
• Added documentation using Doxygen style
• Added self-tests using assert()
• Follows all contribution and file naming guidelines

Checklist

• Added description of change
• File name matches the guidelines
• Added tests and example (all tests pass)
• Added documentation so the program is clear and educational
• Relevant comments added
• PR title follows commit guidelines
• Searched previous suggestions to avoid duplicates
• I acknowledge that all my contributions will be made under the project's license.

Notes

Adds a clear and simple implementation of a palindrome number checker for the math module.