Initial Release of Union QtWidgets

It has begun. After couple months of work, I have now finally managed to cobble together the QtWidgets side of Union. This means that your QtWidgets apps, such as Dolphin, KMail, Kate etc. can now use the Union CSS files as the source of their styling. However, temper your expectations, as this is the first initial release! Do note that there are visual bugs and oddities! I'm still working on things! So yes, as you can see, some things look off. Not Breeze at all! Some things are just different, some other things have wrong colors. These are all fixable and I will do my best to get as many things as possible fixed for the Plasma 6.8 release. But some other oddities are kind of expected: This is the first time ever Breeze QtWidgets and QtQuick style have same shared source-of-truth as an easily editable file! (Excluding colorschemes.) So some of these designs are made with QtQuick in mind, so they can look a bit off in QtWidgets. I'll go through here what I did and what still needs to…