feat: improve/refactor focus handling (#17796)

* feat: improve focus

* test

* lint

* use modulus in loop

web/src/lib/components/elements/buttons/skip-link.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { t } from 'svelte-i18n';
   import Button from './button.svelte';
+  import { getTabbable } from '$lib/utils/focus-util';
 
   interface Props {
     /**
@@ -23,7 +24,12 @@
 
   const moveFocus = () => {
     const targetEl = document.querySelector<HTMLElement>(target);
-    targetEl?.focus();
+    if (targetEl) {
+      const element = getTabbable(targetEl)[0];
+      if (element) {
+        element.focus();
+      }
+    }
   };
 
   const getBreakpoint = () => {