[FIX] web_editor: fix anchor range selection

When we double click a form submit anchor, and depending on the selected
element before click, the selection range ("document.getSelection()") can
start from a parent of the targeted node. This will send a wrong range
to be used in LinkDialog widget.

The goal of this commit is to prevent this behaviour by adjusting the range
if it starts from anchor parent.

Note: the bug only occurred in Firefox.

Part of https://github.com/odoo/odoo/pull/62206
task-2381305

closes odoo/odoo#62206

closes odoo/odoo#67171

closes odoo/odoo#67176

X-original-commit: 9a16c313f131ed2e1017566a5f1bed134e22cc10
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/web_editor/static/lib/summernote/src/js/module/Editor.js

@@ -711,7 +711,13 @@ define([
       var rng = range.create().expand(dom.isAnchor);
 
       // Get the first anchor on range(for edit).
-      var $anchor = $(list.head(rng.nodes(dom.isAnchor)));
+      var anchor = list.head(rng.nodes(dom.isAnchor));
+      const $anchor = $(anchor);
+
+      if ($anchor.length && !rng.nodes()[0].isSameNode(anchor)) {
+        rng = range.createFromNode(anchor);
+        rng.select();
+      }
 
       // Check if the target is a button element.
       let isButton = false;