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.module.scss.d.ts

@@ -0,0 +1,15 @@
+declare namespace LanguageNamespace {
+    export interface ILanguageScss {
+        languageContainer: string;
+        languageContainerMobile: string;
+        languageIcon: string;
+        languageLink: string;
+    }
+  }
+
+declare const LanguageScssModule: LanguageNamespace.ILanguageScss & {
+    /** WARNING: Only available when `css-loader` is used without `style-loader` or `mini-css-extract-plugin` */
+    locals: LanguageNamespace.ILanguageScss;
+  };
+
+  export = LanguageScssModule;