feat(poly check and libs): add --alias option - #112

Description

Useful when an import differ from the library name, such as:
library name "opencv-python" and the actual import is "cv2". This will cause the poly check and poly libs to report missing dependencies.

The --alias option will help the commands with understanding the imports.

Example usage:

poetry poly check --alias opencv-python=cv2

With several aliases:

poetry poly check --alias opencv-python=cv2 --alias matplotlib=mpl_toolkit

Motivation and Context

Partially solves #107

How Has This Been Tested?

Local install and testing with the python-polylith-example repo.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I have read the code of conduct.
• I have read the contributing guide.
• I have updated the documentation accordingly (if applicable).