The user should be better informed when they make a mistake by attempting to create a new record that uses the same named key as an existing record.

For example, right now if I had created a destination named Kafka and decide to create a second one, rather than the form automatically preventing the submission because the name is used or at the very least telling me that a record exists with the same name on submission, the user is presented with

I realize it's a bit more work, but I think in keeping with modern UIs, we likely should handle this in 3 ways:

1. Validate on keystroke and unfocus that the name is permissible and not used.
2. Prevent the create/save buttons from being enabled if the name isn't allowed.
3. On submission, we should return a better error than "Internal Server Error"