Switch to REM API for explore WG page

Signed-off-by: Zhou Fang zhou.fang@eclipse-foundation.org

For eclipsefdn/it/websites/membership.eclipse.org#346 (closed)

Need an update from REM API to be able to fetch all wgs (including those we don't want to display on online application form atm, such as openhw and openhw europe)

Can be previewed here:

https://deploy-preview-315--eclipsefdn-solstice-assets.netlify.app/explore-wg.html

And here:

https://staging.eclipse.org/org/workinggroups/explore.php

js/solstice/eclipsefdn.wgs-list.js

 /*!
- * Copyright (c) 2022 Eclipse Foundation, Inc.
+ * Copyright (c) 2021, 2022 Eclipse Foundation, Inc.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
  * http://www.eclipse.org/legal/epl-2.0.
  *
  * Contributors:
+ *   Christopher Guindon <chris.guindon@eclipse-foundation.org>
+ *   Eric Poirier <eric.poirier@eclipse-foundation.org>
  *   Zhou Fang <zhou.fang@eclipse-foundation.org>
  *
  * SPDX-License-Identifier: EPL-2.0