feat(display-name) remove DisplayNameLabel web

react/features/display-name/components/web/index.js

 // @flow
 
 export { default as DisplayName } from './DisplayName';
-export { default as DisplayNameLabel } from './DisplayNameLabel';
 export { default as DisplayNamePrompt } from './DisplayNamePrompt';
 export { default as DominantSpeakerName } from './DominantSpeakerName';