Use customer_id as the user_id in segment in the webapp.

[cgardens]

When we call identify in the webapp, we are currently letting segment set the user id itself. We are then adding customer_id as an attribute on that user. Instead we want to user the customer_id provided by the API as the user id.

Current code:

      AnalyticsService.identify({
        customerId: workspace.customerId
      });

https://github.com/airbytehq/airbyte/blob/master/airbyte-webapp/src/pages/routes.tsx#L142
Desired:

      AnalyticsService.identify({}, workspace.customerId);

I was trying to do this myself, but was having trouble sanity checking that it was working in the Segment debugger.