Use `ChainMap` to rewrite the cmd options <- configuration file <- default configuration chain

[bearomorphism]

Description

As title. A ChainMap keeps more information and is easier to debug.

Possible Solution

No response

Additional context

https://realpython.com/python-chainmap/#prioritizing-command-line-apps-settings

Related issues

No response

[bearomorphism]

This can be assigned to me, but probably I won't implement until other PRs are merged. There may be some dependencies.