Create is valid email address algorithm (#8907)

* feat(strings): Create is valid email address

* updating DIRECTORY.md

* feat(strings): Create is_valid_email_address algorithm

* chore(is_valid_email_address): Implement changes from code review

* Update strings/is_valid_email_address.py

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* chore(is_valid_email_address): Fix ruff error

* Update strings/is_valid_email_address.py

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

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Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>