Add div wrappers around window controls svg elements

[jakub-chatrny]

Adding div wrapper around svg element allowing change style of window controls easily just by using css.

Reason for PR:

You cant change svg path using css and you can't use :after or :before on element either.

Utilization of PR:

In my plugin hyper-macos-mjv-dark-theme (You can see image in readme)

• PR is ready to merge

• PR allows edits from maintainers

• PR do not make any changes to API

[chabou]

This change could break some existing plugins but it will be easy to fix them.
The new styling possibilities offered are worth this change.

[chabou]

Thank you so much for your help @jakub-chatrny 🙏