When two components have the same label, the components list is empty

If two items in the component catalog have the same label, an angular.js error occurs and the list of components to be added to a container remains empty. See the attached log file with the error.

Reproduction path:

• Create project based on 12.0.2 archetype
• Add banners feature
• Rebuild and start, go to console, change @hst:label of carousel component to Banner: http://localhost:8080/cms/console/?1&path=/hst:hst/hst:configurations/hst:default/hst:catalog/essentials-catalog/carousel
• Log out of the CMS (if you were logged in before) and login to CMS
• Go to Preview mode in Channel Manager, open the side panel and click on the Components tab
• The components list is empty and a JS error can be found in the browser logs (see bottom of issue)

Although the above use case is not one that likely will occur in practice, the use case that can occur and has occurred in some projects is when multiple component catalogs are combined from multiple sites through inheritance.