ARCHBOM-1527: update code owner mapping

[robrap]

Description:

• Exposed existing get_code_owner_from_module via the public api.
• Fixed get_code_owner_from_module to not require a call to is_code_owner_mappings_configured beforehand.
• Set the existing code_owner_path_module custom attribute, even for cases where the transaction name was used, rather than the view module.
• Refactored and simplified configuration and tests.

JIRA:

ARCHBOM-1527

Merge checklist:

• [x] CI build is green
• [x] Version bumped
• [x] Changelog record added
• [x] Documentation updated (not only docstrings)
• [x] Commits are squashed

Post merge:

• [ ] Create a tag
• [ ] Check new version is pushed to PyPi after tag-triggered build is finished.
• [ ] Delete working branch (if not needed anymore)