Make Breeze more round

This is mostly a task list to keep all the merge requests linked and easy to find in one place.

We're now in testing phase, as in, if you see something weird, report/fix it!

In it's simplest explanation, the radius of all buttons and other round elements, is changed from 3 to 5.

Breeze widgets

QQC2 / Kirigami

GTK

Also, if things feel Too Round, we can go back to 4 or even 3 easily since I am using same value everywhere as much as possible. Consistency saves the day!

Alternate title: Make Breeze more uwu