Improve user-list-content performance. close #6268

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

...ebutton-html5/imports/ui/components/nav-bar/component.jsx

...rts/ui/components/nav-bar/settings-dropdown/component.jsx

...rts/ui/components/nav-bar/settings-dropdown/container.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/user-list/user-list-content/breakout-room/component.jsx

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

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

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

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

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

...st-content/user-participants/user-list-item/component.jsx

...st-content/user-participants/user-list-item/container.jsx

...r-participants/user-list-item/user-dropdown/component.jsx

.../user-participants/user-list-item/user-name/component.jsx

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

...list-content/user-participants/user-options/container.jsx

...ents/user-list/user-list-content/user-polls/component.jsx