Add age_controller.py with validate_age function (issue #12809)

[Tejasrahane]

This PR adds a new age_controller.py module that implements the validate_age function to address issue #12809.

Summary:
The age_controller.py module provides robust age validation functionality that:

• Accepts age input as int, str, or float
• Validates that the age is a positive integer within a reasonable range (0-150 years)
• Includes comprehensive error handling for invalid inputs
• Features complete doctests demonstrating various use cases
• Follows all Python type hints and naming conventions

The implementation handles edge cases including negative numbers, out-of-range values, and invalid string inputs.

Describe your change:

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes Need help for my age controller #12809".

Fixes #12809