Replacing global themed sass-vars to css-vars (#4322)

* generating css-vars
* convert all global / theme sass vars to css vars with available default theme colors
* added missing colors to dark lens theme

src/renderer/components/+network/network-mixins.scss

@@ -20,8 +20,8 @@
  */
 
 $service-status-color-list: (
-  active: $colorOk,
-  pending: $colorWarning
+  active: var(--colorOk),
+  pending: var(--colorWarning)
 );
 
 @mixin service-status-colors {
@@ -33,7 +33,7 @@ $service-status-color-list: (
 }
 
 $port-forward-status-color-list: (
-  active: $colorOk,
+  active: var(--colorOk),
 );
 
 @mixin port-forward-status-colors {