When selecting conversion goal, select another goal for test

Description

When creating an A/B test, if I select a KPI from the dropdown for available conversion goals, a second dropdown appears below the KPI's markup that contains options for assigning another KPI to the test.

Selecting a KPI from the dropdown

• Adds a kpi below the dropdown. This is the same information as before (kpi Title, description and accompanying markup)
• Kpi now has an "X", which allows the KPI to be removed.

Kpi Types and Counts

• Only boolean result type kpis can have multiple kpis added to a test.
• If a boolean result type is chosen, non-boolean result type kpis should be removed from the kpi select list. (Currently, the only non-boolean result type kpi is Average Order Kpi, available in the Commerce kpi package.)
• Up to 5 boolean result type kpis can be added to a single test.
• When 1 boolean result type kpi is added, the default item in the dropdown should indicate the ability to add more kpis.
• When 5 boolean result type kpis are added, the dropdown should no longer be seen.
• If a kpi is removed, the dropdown should be redrawn.
• if a kpi is removed, its associated weight selector should also be removed.
• if a non-boolean result type kpi is added, the dropdown should no longer be seen (if removed, the dropdown should return).