Reworked modal to dynamically change content

...ts/ui/components/audio-modal/audio-settings/component.jsx

...ton-html5/imports/ui/components/audio-modal/component.jsx

...mports/ui/components/audio-modal/join-audio/component.jsx

...ports/ui/components/audio-modal/listen-only/component.jsx

...utton-html5/imports/ui/components/audio-modal/styles.scss

bigbluebutton-html5/public/resources/images/allow-mic.png

bigbluebutton-html5/public/svgs/bbb_audio_icon.svg

bigbluebutton-html5/public/svgs/bbb_headphones_icon.svg