Introduce services to make testing easier

Please see the merge request. The logic for estimating the read time has not changed. Merely moved to services. I am not completely convinced on the naming of the services, yet. Naming is the hardest - open for feedback.

Rerolled after 🐛 Estimated Read Time module make webform send emails twice Fixed !

Thank you for your contributions @simonbaese! I have tested the changes and everything is working as expected. I created a new release today and will merge this into dev.

Automatically closed - issue fixed for 2 weeks with no activity.