Refactor generic native python container image functionality into containerimage-py

## Overview

Hi all, I just recently stood up a project in the containers org that I'd like to try to turn into a python-native alternative to the Go containers/image library. Its repository is located here, and it is very early in its life at this point.
- https://github.com/containers/containerimage-py

I wanted to reach out across the other Python projects in this org to understand what sort of generic containerization implementation exists that can be shifted into `containerimage-py`. If none / not interested, no worries. If there is some interest, I thought it might make some sense to try to shift what we can into a common library much like containers/image and containers/common underly many of the Go-based projects in this org.

I figured we could use this issue for further discussion

## Acceptance

- [ ] Potential common functionality which can be shifted into `containerimage-py` is discussed
- [ ] Issues are planned across the relevant repositories to shift common functionality into `containerimage-py`