feat: add reverse_integer

[Rfontt]

Description of Change

This PR introduces an implementation of the integer reversal algorithm (reverse_integer) following the project's style and educational guidelines.
The function safely reverses a 32-bit signed integer while preventing overflow by checking against INT32_MAX and INT32_MIN.

• Added description of change
• Added a new file reverse_integer in operations_on_datastructures
• Added tests and example, test must pass
• Added documentation so that the program is self-explanatory and educational - Doxygen guidelines
• 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 to review:

Time Complexity: O(log₁₀(n))

• Each loop iteration removes one digit (number = number / 10).
• An integer with value n has log₁₀(n) digits.
• Therefore, the loop runs once per digit.

Example:

• 123 → 3 iterations
• 123456789 → 9 iterations
• up to 32-bit max → at most 10 iterations

Space Complexity: O(1)

• It uses only a fixed number of variables: reversed, digit, and the input itself.
• No dynamic allocation.
• No additional data structures.