Remove drupalSettings and eventually twig / view_settings arrays

@thomas.frobieter: This please still needs manual tests. If simple enough, you can tell @Grevil how to do it. Assigning him for information.

I'd need to setup a test enviroment, its probably faster for @Grevil to test this.
I think most of the options are self explaining? I am happy to assist, if you have any questions @Grevil.

Check the Foundation demos, to see the desired result:
https://get.foundation/sites/docs/accordion.html

Eh, is there a reason this was coded against 8.x-1.x instead of 2.x?

Just in case, I'll create a second branch.

Created:
15 Jan 2019 at 20:46 CET

was the reason, I guess. Was just not changed afterward. But if we're lucky, the code should be very similar ;)

POSTPONED on 🐛 Accordion not opening Postponed: needs info .