Add support to run Commitlint against commit messages. It supports the
current modes:
- Lint the commit message of the last commit
- Lint the commit messages of the pushed commits in case there is more
than one pushed commit
This commit also removes stuff that we used to run commitlint as a
standalone tool because we can now use the commitlint instance that
Super-linter ships:
- lint-commit steps in lint-commit the GitHub Actions workflow
- lint-commit Make target
- commitlint and its dependencies in package.json and package-lock.json
- Remove the previous summary file is present to avoid showing stale
contents from old summaries.
- Extract the logic to write summary heading and lines to dedicated
functions in output.sh to make it easier adding new formats in the
future.
