User is able to give a Preview Scene Profile the same name as an existing profile

In the Preview Scene Settings, the user is able to give two profiles the same name.

While this doesn't result in any issues, it is something that's generally not accepted in the editor and can cause confusion.

1. Open QAGame in editor.
2. Open the skeletal mesh SK_Mannequin in Persona.
3. In the Preview Scene Settings, name the current profile "Test".
4. Click Add Profile.
5. Switch to the new profile.
6. Name the new profile "Test" as well.

RESULT:

The name is accepted, resulting in two profiles named "Test".