Upgrade the boilerplate code to the latest Flask version

[brianbirir]

Goal

• Upgrade to Flask version 3.0.1
• Replace Restful with RestX: https://github.com/python-restx/flask-restx
• Implement web hook capability
• Usage of pipenv to manage Python packages and virtual environment
• Enhance logging by implementing struct log

Context

• Current Flask version is 2.2.5. In addition Flask-Restful is no longer maintained
• requirements.txt is used for package management

 Issue

20

[brianbirir]

Notes on implementing Pytest: https://testdriven.io/blog/flask-pytest/