[AAE-5637] Remove SCSS mixins and use CSS variables (#7250)

* remove default-class mixin and use regular import

* cleanup colors

* remove variables file, fix bugs in animations

* proper ordering of imports, core css vars

* cleanup snackbar and material themes

* tags component

* login component styles

* app login

* toolbar component styles

* breadcrumb styles

* dropdown breadcrumb

* app layout component

* demo shell: files component

* aspect list styles

* content metadata styles

* node selector

* name location cell

* node share dialog

* content type dialog

* folder dialog

* document list

* datatable theme

* pagination theme

* viewer theme

* viewer theme

* user-info theme

* container widget

* dynamic table theme

* form widgets

* form theme

* form renderer

* sidebar menu

* header theme

* info drawer theme

* comment list

* commens and layout container

* sidenav layout

* empty content

* error content

* clipboard theme

* search input

* tooltip card and notification history

* card view theme

* remove unused keys

* add permission dialog

* search and permission dialogs

* version comparison and column themes

* upload drag area and cleanup references

* remove the need for content styles

* insight components

* cleanup insights theme

* process components

* process components

* process cloud themes

* cleanup unsed imports

* cleanup mixins

* update build scripts

* test fixes

* remove fdescribe

* css fixes

* update unit tests

lib/content-services/src/lib/upload/components/upload-drag-area.component.ts

@@ -25,6 +25,7 @@ import { UploadBase } from './base-upload/upload-base';
 @Component({
     selector: 'adf-upload-drag-area',
     templateUrl: './upload-drag-area.component.html',
+    styleUrls: ['./upload-drag-area.component.scss'],
     host: {'class': 'adf-upload-drag-area'},
     viewProviders: [
         {provide: EXTENDIBLE_COMPONENT, useExisting: forwardRef(() => UploadDragAreaComponent)}