Webpack 5 support with updated packages (#131)

- Update to Webpack 5
- Use @effortlessmotion dynamic html and inline source plugins
- Remove .clasp.json and use SAMPLE file
- Consistent prettier formatting throughout
- Update packages to latest versions

Co-authored-by: Kevin Malakoff <kmalakoff@gmail.com>

test/utils/open-addon.js

@@ -1,4 +1,4 @@
-const openAddon = async page => {
+const openAddon = async (page) => {
   await page.goto(process.env.SHEET_URL);
 
   await page.click('a:nth-child(2)'); // click on signin button
@@ -22,7 +22,7 @@ const openAddon = async page => {
     )
   ) {
     try {
-      await page.click('div[data-accountrecovery]');
+      await page.click('li:nth-child(3)');
       await page.waitForTimeout(6000);
     } catch {
       // eslint-disable-next-line no-console