Adds schemaVersion for cube to automatically detect schema change

What does this MR do and why?

Describe in detail what your merge request does and why.

Relates to gitlab-org/gitlab#460034 (closed)

How to set up and validate

1. Run cube in production mode in a cluster. Upgrade the deployment by running helm upgrade -f custom.values.yaml [RELEASE_NAME]

2. Create a new funnel or update existing funnel by making an api call to /funnel-schemas endpoint in analytics manager.

   POST http://{analytics-configurator-endpoint}/funnel-schemas
   Authorization: Basic [AUTH_USERNAME] [AUTH_PASSWORD]
   Content-Type: application/json
   
   {
     "project_ids": ["gitlab_project_#{id}"],
     "funnels": [
       {
         "name": "completed_purchase",
         "schema": "SELECT (SELECT max(derived_tstamp) FROM gitlab_project_#{id{.snowplow_events) as x, windowFunnel(3600)(toDateTime(derived_tstamp), page_urlpath = ''/page1.html'', page_urlpath = ''/page2.html'') as step FROM gitlab_project_#{id}.snowplow_events",
         "state": "created"
       }
     ]
   }

   OR

   Run GDK locally. Create a new funnel in any repository.

3. Make an API call to cubejs /v1/meta endpoint to see the cube schema defined. It should have the new cube funnel schema definition.

4. Try updating/deleting a funnel too. It should be reflected immediately in the cubes (/v1/meta) endpoint without a restart.

How to deploy upon merging

Numbered steps to explain how this change needs to be deployed to each environment.