refactor(themes): consume spacing from theming package

Author: simeonoff

src/styles/themes/base/_theme.scss

@@ -18,9 +18,6 @@
     :root {
         --ig-theme: #{map.get($palette, '_meta', 'variant')};
         --ig-theme-variant: #{$variant};
-        --ig-spacing: 1;
-        --ig-spacing-inline: 1;
-        --ig-spacing-block: 1;
         --ig-size-small: 1;
         --ig-size-medium: 2;
         --ig-size-large: 3;
@@ -37,5 +34,6 @@
         $font-family: $typeface,
         $type-scale: $type-scale
     );
+    @include spacing();
 }