Convert global configuration to vocabulary third party settings

Thank you very much @rp7!
Could you perhaps provide the changes as MR?

Should we have additional tests or is everything covered?

Thanks! :)

Alright all finished and tested:

• The submission works as expected and the settings are unique to the vocabulary and behave as expected (tested "enabled" true / false and "message" empty / default / changed)
• The update hook works flawlessly
• The test coverage is fairly decent! No need to add further tests for now (Although we could create a follow up issue to add a few more)

Great work @rp7 and @Grevil! :) Made some minor textual improvements, now I think it's ready to go.

@Grevil says it's fine, the tests say it's fine, so it's merge time! :)

Fixed! We'll keep this in .dev for some weeks.

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