Breaking: #68116 - Drop RTE.userLinks functionality 

See forge#68116

Description 

Drop RTE.userLinks functionality from the ElementBrowser. The option was broken since 6.0 and has been removed now.

Impact 

The special option won't show up in the ElementBrowser anymore.

Affected Installations 

All installations which use the option RTE.userLinks

Migration 

Use the newly added Tabbing API to add your custom link selection tab.