[FIX] web_editor: limit custom table selection to editable area bounds

The custom table selection was not limited to the editable area bounds,
which means we could end up styling a table as selected, which did not
belong to the editor's scope. This sometimes happened when Firefox
triggered a selectionchange event during the instantiation of the editor
and the selection happened to be in a table outside the editor.

opw-3150654
task-3166078

closes odoo/odoo#111779

X-original-commit: d51aab54775ed541d7955cee032aceed143d3a08
Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>

addons/web_editor/static/src/js/editor/odoo-editor/src/OdooEditor.js

@@ -2204,7 +2204,7 @@ export class OdooEditor extends EventTarget {
     _handleSelectionInTable(ev=undefined) {
         const selection = this.document.getSelection();
         const anchorNode = selection.anchorNode;
-        if (anchorNode && closestElement(anchorNode, '[data-oe-protected="true"]')) {
+        if (anchorNode && (closestElement(anchorNode, '[data-oe-protected="true"]') || !ancestors(anchorNode).includes(this.editable))) {
             return false;
         }
         this.deselectTable();