Introduce a GitHub action to validate the PR name

[nivisi]

As we follow conventional commits, it would be nice to use this format for PR names as well.

fix/feat/chore/etc(TICKET-XXX): Name of the ticket
fix/feat/chore/etc: Changes description

To force that, we can introduce a GitHub action that validates it. I've something similar in my pet project where I validate PRs. But's a bit more complex and checks for ticket name and for the description.