[FIX] web_editor: stop snippet editors from finding widget in parent

Because of the event propagating to an option's parent, a snippet option
requesting a uservalue widget would also get back the corresponding
widgets on the parent snippetEditor, this has the potential to cause
unforeseen problems. This commit fixes that by stopping the event's
propagation.

closes odoo/odoo#46724

X-original-commit: 1441b3c2f4f935771b3210be82f7b471aa028b64
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/web_editor/static/src/js/editor/snippets.editor.js

@@ -774,6 +774,7 @@ var SnippetEditor = Widget.extend({
      * @param {Event} ev
      */
     _onUserValueWidgetRequest: function (ev) {
+        ev.stopPropagation();
         for (const key of Object.keys(this.styles)) {
             const widget = this.styles[key].findWidget(ev.data.name);
             if (widget) {