[ML] Initial serverless functional tests for ML (#167493)

Add serverless functional tests for each project.

**Search**
Opens the trained models page and checks that there are 4 models listed.

**Observability**
Creates a AD job and then navigates to the AD jobs list and checks that
the job is listed.

**Security**
Creates a AD job and then navigates to the AD jobs list and checks that
the job is listed.
Creates a DFA job and then navigates to the DFA jobs list and checks
that the job is listed.
Navigates to the trained models page and checks that there are no
trained models listed.

Also adds tests for each project to ensure that kibana search bar only
lists the pages which are enabled.

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/ml/public/register_helper/register_search_links/search_deep_links.ts

@@ -263,7 +263,7 @@ function createDeepLinks(
       };
     },
 
-    getDataComparisonDeepLink: (): AppDeepLink<LinkId> => {
+    getDataDriftDeepLink: (): AppDeepLink<LinkId> => {
       return {
         id: 'dataDrift',
         title: i18n.translate('xpack.ml.deepLink.dataDrift', {