Provide a single script to report all errors

[CodingCanuck]

When developing locally, it's nice to be able to run a script to reproduce formatting errors reported by the GitHub Actions Runner (for example: https://github.com/reboot-dev/respect/runs/7011852919?check_suite_focus=true )

Currently, the GitHub Action Runner runs three steps in sequence to find and report all formatting errors: https://github.com/3rdparty/dev-tools/blob/main/check-code-style/action.yml#L37-L56

Can we offer a single script that does all of these things for local execution? (We could then maybe simplify the Action Runner config to just call that one unified script)