Add coreutils module

[giswqs]

• Creates the coreutils module by extracting functions that core modules rely on from the common module.
• Replaces from . import common with from . import coreutils
• Replaces function calls common.*** with coreutils.***
• Adds typehints and docstrings to all functions in coreutils
• Add coreutils module to mkdocs

[github-actions]

🚀 Deployed on https://66ec4933857b090d6302c5e9--opengeos.netlify.app

[giswqs]

@naschmitz This is test