Feature Request: Add MyPy check to test whether every code has a type hint

[unna97]

Is your feature request related to a problem? Please describe.
Add mypy & other pre-commit hooks to test & validate the code quality

[unna97]

• MyPy & type hints for sql
  Resources:

1. https://github.com/dropbox/sqlalchemy-stubs
2. https://calpaterson.com/mypy-hints.html
3. https://docs.sqlalchemy.org/en/14/orm/extensions/mypy.html#installation