Chore: Send browser language in webwidget events (#952)

Co-authored-by: Pranav Raj Sreepuram <pranavrajs@gmail.com>

app/javascript/widget/helpers/specs/urlParamsHelper.spec.js

@@ -0,0 +1,16 @@
+import { buildSearchParamsWithLocale } from '../urlParamsHelper';
+
+jest.mock('vue', () => ({
+  config: {
+    lang: 'el',
+  },
+}));
+
+describe('#buildSearchParamsWithLocale', () => {
+  it('returns correct search params', () => {
+    expect(buildSearchParamsWithLocale('?test=1234')).toEqual(
+      '?test=1234&locale=el'
+    );
+    expect(buildSearchParamsWithLocale('')).toEqual('?locale=el');
+  });
+});