[FIX] web_editor: prevent creating a link when it already exists

Before this commit
The method `getOrCreateLink` did not return the startNode when the
startNode was a link.

If the startNode is a link, we should not try to get the link from the
selection as we already have the link. Getting the link from the
selection should be a fallback.

When clicking on a link that within a `contenteditable=false`, because
the link startNode was not returned, the element from the selection was
not the link and `getOrCreateLink` created a new link.

task-2967314

closes odoo/odoo#99864

X-original-commit: c50c2b025c58408b2e90b7b25430c981d0bcdc2b
Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>

addons/web_editor/static/src/js/wysiwyg/widgets/link.js

@@ -502,9 +502,13 @@ const Link = Widget.extend({
  */
 Link.getOrCreateLink = ({ containerNode, startNode } = {})  => {
 
-    if (startNode && !$(startNode).is('a')) {
-        $(startNode).wrap('<a href="#"/>');
-        return { link: startNode.parentElement, needLabel: false };
+    if (startNode) {
+        if ($(startNode).is('a')) {
+            return { link: startNode, needLabel: false };
+        } else {
+            $(startNode).wrap('<a href="#"/>');
+            return { link: startNode.parentElement, needLabel: false };
+        }
     }
 
     const doc = containerNode && containerNode.ownerDocument || document;