Merge pull request #4683 from KDSBrowne/z14-fix-userlist-keyboard-accessibility

...ui/components/settings/submenus/application/component.jsx

...utton-html5/imports/ui/components/user-list/component.jsx

...utton-html5/imports/ui/components/user-list/container.jsx

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

...s/ui/components/user-list/user-list-content/component.jsx

...rts/ui/components/user-list/user-list-content/styles.scss

...s/user-list/user-list-content/user-messages/component.jsx

...er-list/user-list-content/user-participants/component.jsx

...rticipants/user-list-item/user-list-content/component.jsx

...ts/ui/components/user-list/user-list-header/component.jsx

...orts/ui/components/user-list/user-list-header/styles.scss