Implement downloads page and May 25th timed copy changes (#1653)

* Add initial side nav

* Add Download page as a sub-page under Meth&Data

- udpate S3 file path in .envs
- remove the DownloadPacket component
- move download copy from methodology to download
- modify header to use two types of navs:
--  mobile (with sub-pages) and
-- desktop (without subpages)
- create a SubPageNav component
- add SubPagNav to Meth and Download page
- update snapshots
- add global CSS overide to remove minus sign on mobile nav link accordion as it's permanently open

* Remove the update tag above Public eng button

* Make the 3rd bullet on explore page update on 5/25

* Make the RFI box text change after 5/25/22

* Update site with RFI expired copy, remove Alerts

- add Spanish translations
- update snapshots

* Fix typo on XLS file path

* Refactor HowYouCanHelp to standard form

* Add custom download links with icons

- add new DownloadLink compnent
- add Spanish translations

* Update download file sizes

* Allow meth&data nav link to collapse on mobile

client/src/components/DownloadLink/DownloadLink.tsx

@@ -0,0 +1,40 @@
+import React from 'react';
+import {defineMessages, useIntl} from 'gatsby-plugin-intl';
+
+import {IDefineMessage} from '../../data/copy/common';
+
+// @ts-ignore
+import fileDownloadIcon from '/node_modules/uswds/dist/img/usa-icons/file_download.svg';
+import * as styles from './DownloadLink.module.scss';
+
+export const DOWNLOAD_ICON = defineMessages({
+  ALT_TAG: {
+    id: 'downloads.page.download.icon.alt.tag',
+    defaultMessage: 'The icon used to indicate that the file is downloadable',
+    description: 'Navigate to the Downloads page, this is the icon used to indicate that the file is downloadable',
+  },
+});
+
+interface IDownloadLink {
+    href: string | IDefineMessage,
+    linkText: string | JSX.Element,
+}
+const DownloadLink = ({href, linkText}:IDownloadLink) => {
+  const intl = useIntl();
+
+  if (href && typeof href !== `string`) {
+    href = intl.formatMessage(href);
+  }
+  return (
+    <>
+      <a href={href} download>{linkText}</a>
+      <img
+        className={styles.downloadIcon}
+        src={fileDownloadIcon}
+        alt={intl.formatMessage(DOWNLOAD_ICON.ALT_TAG)}
+      />
+    </>
+  );
+};
+
+export default DownloadLink;