[INFRA] Enforce usage of conventional commits for Pull Request titles

[tbouffard]

Rationale: see Enforce Conventional Commits for PR title (view)

Tasks

• create the GitHub workflow the enforce PR Title. It runs on pull_request_target to handle PR created by Dependabot and from fork repositories. It will be triggered once the PR introducing it is merged. See ci(pr-title): use a new shared action .github#23 (comment)
• update the GitHub workflows creating commits and pull requests. Also change the name of the created branches (infra to chore to match CC): not applicable in this repository
• update the Dependabot configuration. Use an explicit configuration as by default, Dependabot use the commits in the repository which don't follow "conventional commits"
• PR Template and/or contributing guide: not applicable in this repository
• npm script (commit creation for release): not applicable in this repository
• detect other impacts: search for string [ or ] in GitHub workflows, npm package, ...: none here

See also process-analytics/github-actions-playground#213 and process-analytics/github-actions-playground#224