Add language links to switch between English and Spanish (#842)

* Add language links to gov banner

- align banners to site logo
- create Language component and snapshot test
- add Language component to GovBanner
- update namespace for betaBanner scss.d.ts file

* Update snapshots for each page

* Componentizes the GovBanner

- add styles
- add unit test
- token most styles to USWDS

* Add language icon and update snapshots

* Make language link text smaller

* Update total height of BetaBanner

* Add languageLink to scss.d.ts file

* Add language links to mobile

- add isDesktop prop to Language component
- refactors header links to a simple array
- update snapshots

* Add href value to language links

- update snapshots

* merge other PRs and add spanish links

- merge PR 817
- merge PR 794
- add spanish links for footer
- add diffEnEs.js to detect differences between two json files
- adds esNoBrackets.json
- update intl README

* Add government banner in spanish

* Add spanish content for About and Explore page

client/src/components/Language/Language.test.tsx

@@ -0,0 +1,16 @@
+import * as React from 'react';
+import {render} from '@testing-library/react';
+import {LocalizedComponent} from '../../test/testHelpers';
+import Language from './Language';
+
+describe('rendering of the Language', () => {
+  const {asFragment} = render(
+      <LocalizedComponent>
+        <Language />
+      </LocalizedComponent>,
+  );
+
+  it('checks if component renders', () => {
+    expect(asFragment()).toMatchSnapshot();
+  });
+});