Refactored base page and started chat saving test

bigbluebutton-html5/tests/puppeteer/.gitignore

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

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

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

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

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

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

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

bigbluebutton-html5/tests/puppeteer/downloads/downloads.txt

bigbluebutton-html5/tests/puppeteer/page-draw.js

bigbluebutton-html5/tests/puppeteer/page-status.js

bigbluebutton-html5/tests/puppeteer/page-switch-slides.js

bigbluebutton-html5/tests/puppeteer/page-upload.js

bigbluebutton-html5/tests/puppeteer/page.js