Add a workflow that automatically manages a code-owner-approved label
on PRs when component-specific codeowners submit approvals. This helps
maintainers prioritize PRs that have domain-expert sign-off.
The workflow triggers on pull_request_review events and recalculates
the label based on all current reviews. Only individual component
codeowners count - the catch-all @esphome/core team is excluded.
Uses last-match-wins semantics for CODEOWNERS pattern matching.
Also extracts shared CODEOWNERS parsing logic into a reusable module
at .github/scripts/codeowners.js and updates codeowner-review-request
and auto-label-pr workflows to use it.
J. Nick Koston