Added new algorithm to solve the famous celebrity problem using stack - #13112

Problem Description : Find the celebrity in a party.

A celebrity is a person who:
- Is known by everyone else
- Knows no one else

Args:
    mat: n x n adjacency matrix where mat[i][j] == 1 if person i knows person j.

Returns:
    Index of the celebrity if one exists, else -1.

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 #ISSUE-NUMBER".