Add HaTS link to the main page (#2028)

* Add screen_view, ad_impression, campaign_details events to EventBuilder

* remove UA toggle

* update the react-spinner version

* remove unimplemented LineItem component

* Force Typography to use span tag instead of div to avoid compilation warnings. Remove duplicate code and fix tests by renaming labels...

* remove UA code and tests

* fix tests

* Dimensions and Metrics Explorer UX update

Use the autocomplete component to search metrics/dimensions.
The main list of all dimensions/metrics remains unchanged when selecting fields for compatibility check.
The list of options available in Autocomplete components is updated based on fields' compatibility.
Display field categories in accordion with Expand all / Collapse all options.
Add option to display compatible only/incompatible only/all fields.
Render field description using Markdown.

* add HATS survey link to the main page under the "Help & Feedback" section

src/components/Home/index.tsx

@@ -88,6 +88,13 @@ const IndexPage: React.FC = () => {
       </Typography>
       <Typography variant="h3">For this site</Typography>
       <Typography variant="body1" component="ul">
+        <li>
+          Fill out a{" "}
+          <ExternalLink href={Url.gaDevToolsHatsSurvey}>
+            brief customer survey
+          </ExternalLink>{" "}
+          and let us know what you think!
+        </li>
         <li>
           You may report bugs by{" "}
           <ExternalLink href={Url.gaDevToolsGitHubNewIssue}>

src/constants.ts

@@ -52,6 +52,8 @@ export enum Url {
   enhancedEcommerceDemo = "https://enhancedecommerce.appspot.com/",
   gaDevToolsGitHub = "https://github.com/googleanalytics/ga-dev-tools",
   gaDevToolsGitHubNewIssue = "https://github.com/googleanalytics/ga-dev-tools/issues/new?assignees=&labels=&template=bug_report.md&title=",
+
+  gaDevToolsHatsSurvey = "https://forms.gle/khM6TxwTpjRfkPk69",
   gaDevToolsGitHubNewFeatureRequest = "https://github.com/googleanalytics/ga-dev-tools/issues/new?assignees=&labels=&template=feature_request.md&title=",
   gaDevsite = "http://developers.google.com/analytics",
   gaDevsiteHelp = "http://developers.google.com/analytics/help/",