move views_ui.admin.theme.css to seven

Postponed because

• Seven is no longer in core (so at minimum an issue summary is needed), Claro would likely be the current equivalent.
• Super-starkening is not necessarily the priority it once was, and this issue was filed 8 years ago. Given that this asset moving might be disruptive, it would be good to consider if the change is beneficial enough to justify that disruption.

Wonder if this is still needed?

Wonder if this is still needed?

I'll make the call. These CSS moving efforts were worth pursuing when Drupal 8 was in development - but now that it's been around close to a decade such a change would be more disruptive than beneficial.

Thanks!