refactor user role management to follow proper format

...uebutton-html5/imports/api/breakouts/server/publishers.js

...luebutton-html5/imports/api/meetings/server/publishers.js

...ton-html5/imports/api/users/server/handlers/changeRole.js

...l5/imports/api/users/server/handlers/presenterAssigned.js

...utton-html5/imports/api/users/server/modifiers/addUser.js

...ml5/imports/api/users/server/modifiers/changePresenter.js

...on-html5/imports/api/users/server/modifiers/changeRole.js

bigbluebutton-html5/imports/api/users/server/publishers.js

...components/actions-bar/create-breakout-room/component.jsx

bigbluebutton-html5/imports/ui/components/audio/service.js

...uebutton-html5/imports/ui/components/user-list/service.js

bigbluebutton-html5/private/config/settings.yml