fix: replace hardcoded values with scss variable, correct background image syntax

Author: yordan-st

packages/atlas/src/themesource/atlas_core/web/layouts/_layout-atlas.scss

@@ -107,8 +107,8 @@
                     @if $brand-logo !=false {
                         width: 0;
                         height: 0;
-                       padding: calc(var(--brand-logo-height, 32px) / 2) calc(var(--brand-logo-width, 32px) / 2);
-                        background-image: url(#{$brand-logo});
+                       padding: calc(var(--brand-logo-height, $brand-logo-height) / 2) calc(var(--brand-logo-width, $brand-logo-height) / 2);
+                        background-image: url(var(--brand-logo, #{$brand-logo}));
                         background-repeat: no-repeat;
                         background-position: left center;
                         background-size: var(--brand-logo-width);