[WIP] adds visual regression testing

bigbluebutton-html5/package.json

bigbluebutton-html5/tests/puppeteer/.env-template

bigbluebutton-html5/tests/puppeteer/audio.obj.js

bigbluebutton-html5/tests/puppeteer/breakout.obj.js

bigbluebutton-html5/tests/puppeteer/chat.obj.js

bigbluebutton-html5/tests/puppeteer/chat/util.js

bigbluebutton-html5/tests/puppeteer/customparameters.obj.js

bigbluebutton-html5/tests/puppeteer/jest.config.js

bigbluebutton-html5/tests/puppeteer/notifications.obj.js

bigbluebutton-html5/tests/puppeteer/presentation.obj.js

bigbluebutton-html5/tests/puppeteer/screenshare.obj.js

bigbluebutton-html5/tests/puppeteer/sharednotes.obj.js

bigbluebutton-html5/tests/puppeteer/user.obj.js

bigbluebutton-html5/tests/puppeteer/virtualizedlist.obj.js

bigbluebutton-html5/tests/puppeteer/webcam.obj.js

bigbluebutton-html5/tests/puppeteer/webcamlayout.obj.js

bigbluebutton-html5/tests/puppeteer/whiteboard.obj.js