[Editor] Add the possibility to create an highlight from the context menu when some text is selected (bug 1867739)

test/integration/freetext_editor_spec.mjs

@@ -2829,7 +2829,7 @@ describe("FreeText Editor", () => {
             count: 3,
           });
           const selection = await page.evaluate(() =>
-            window.getSelection().toString()
+            document.getSelection().toString()
           );
 
           expect(selection).withContext(`In ${browserName}`).toEqual(data);