Add CSS variable counterparts for (almost) every SCSS variable

[NickdeK]

Personally I'm a big fan of reducing complexity and dependencies in a project, and in the last 5 years or so I find the need to use Sass demising and recently I even started to question if Sass still has a place in the modern frontend stack.

Multiple futures are used in the framework like; variables, nesting and mixins. I do realize that not all can be replaced with vanilla CSS features (specially the mixins). And to be clear; I'm not advocating to get rid of the Sass completely as that will be a tall order. But it would be nice if the build version of Quasar would supply a nice CSS file that includes everything and uses CSS variables so that users could get rid of the extra Sass layer in their project frontend stack while maintaining the feature of changing the style of components. At the moment I have to use a variables scss file in my project to change those variables and use scss style blocks to use those variables. CSS variables can do the same thing and it would remove the need for Sass in a project altogether for most projects.

In the framework it could be as easy as setting the sass variable to use the css variable and just define and use those everywhere. With only this change Sass in the frontend build won't be needed I think?