[FIX] barcodes: handle error message on barcode scanning

Before this commit:
Got a traceback instead of an error message on scanning a barcode.

Reason:
Until 16.4 error message send in the object via Eventbus, which removed in
https://github.com/odoo/odoo/commit/72dbb75d4de529a35c45273ded472d038a7bb738 so because of that error message will be sent directly(not in object).

After this commit:
User will get an error message if anything wrong happened.

Task:3524284

closes odoo/odoo#138877

Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

addons/barcodes/static/src/components/barcode_scanner.js

@@ -21,7 +21,7 @@ export class BarcodeScanner extends Component {
         try {
             barcode = await scanBarcode(this.env, this.facingMode);
         } catch (err) {
-            error = err.error.message;
+            error = err.message;
         }
 
         if (barcode) {

addons/barcodes/static/tests/basic/barcode_scan_tests.js

@@ -0,0 +1,32 @@
+/** @odoo-module **/
+
+import { BarcodeScanner } from "@barcodes/components/barcode_scanner";
+import { getFixture, mount } from "@web/../tests/helpers/utils";
+import { contains } from "@web/../tests/utils";
+import { createWebClient } from "@web/../tests/webclient/helpers";
+
+import { xml, Component } from "@odoo/owl";
+
+QUnit.module("Barcode scan", {});
+
+QUnit.test("Display notification for media device permission on barcode scanning", async () => {
+    navigator.mediaDevices.getUserMedia = function() {
+        return Promise.reject(new DOMException("", "NotAllowedError"));
+    };
+
+    class BarcodeScan extends Component {}
+    BarcodeScan.components = { BarcodeScanner };
+    BarcodeScan.template = xml`
+        <div>
+            <BarcodeScanner onBarcodeScanned="(ev) => this.onBarcodeScanned(ev)"/>
+        </div>
+    `;
+
+    const target = getFixture();
+    const { env } = await createWebClient({});
+    await mount(BarcodeScan, target, { env });
+
+    await document.querySelector('.o_mobile_barcode').click();
+    await contains(".o_notification", { text: "Could not start scanning. Odoo needs your authorization first." });
+
+})