fix: #438 External URL icon has strange underline (#439)

packages/volto-light-theme/news/438.bugfix

@@ -0,0 +1 @@
+Removed the non-breaking space from the external URL icon, removing the strange underline. @Tishasoumya-02

packages/volto-light-theme/src/theme/_variables.scss

@@ -424,8 +424,12 @@ $line-heights: (
 }
 
 @mixin external-link-icon() {
-  display: inline;
-  content: '\a0'
-    url("data:image/svg+xml,%3Csvg aria-hidden='true' focusable='false' data-prefix='fas' data-icon='external-link-alt' class='svg-inline--fa fa-external-link-alt fa-w-16' role='img' xmlns='http://www.w3.org/2000/svg' viewBox='0 0 512 512' width='11' height='11' %3E%3Cpath fill='%23007EB1' d='M432,320H400a16,16,0,0,0-16,16V448H64V128H208a16,16,0,0,0,16-16V80a16,16,0,0,0-16-16H48A48,48,0,0,0,0,112V464a48,48,0,0,0,48,48H400a48,48,0,0,0,48-48V336A16,16,0,0,0,432,320ZM488,0h-128c-21.37,0-32.05,25.91-17,41l35.73,35.73L135,320.37a24,24,0,0,0,0,34L157.67,377a24,24,0,0,0,34,0L435.28,133.32,471,169c15,15,41,4.5,41-17V24A24,24,0,0,0,488,0Z'%3E%3C/path%3E%3C/svg%3E");
+  display: inline-block;
+  width: 11px;
+  height: 11px;
+  background-color: var(--link-foreground-color, #0070a2);
+  content: '';
+  mask: url("data:image/svg+xml,%3Csvg aria-hidden='true' focusable='false' data-prefix='fas' data-icon='external-link-alt' class='svg-inline--fa fa-external-link-alt fa-w-16' role='img' xmlns='http://www.w3.org/2000/svg' viewBox='0 0 512 512'%3E%3Cpath d='M432,320H400a16,16,0,0,0-16,16V448H64V128H208a16,16,0,0,0,16-16V80a16,16,0,0,0-16-16H48A48,48,0,0,0,0,112V464a48,48,0,0,0,48,48H400a48,48,0,0,0,48-48V336A16,16,0,0,0,432,320ZM488,0h-128c-21.37,0-32.05,25.91-17,41l35.73,35.73L135,320.37a24,24,0,0,0,0,34L157.67,377a24,24,0,0,0,34,0L435.28,133.32,471,169c15,15,41,4.5,41-17V24A24,24,0,0,0,488,0Z'/%3E%3C/svg%3E")
+    no-repeat center;
   white-space: nowrap;
 }