Introduce FontAwesome 5 with scss files and remove from gulp

• First bunch of template changes
• Change of CKEditor plugin (now you need to set all classes)

How to test:

1. Setup one website (extensions.typo3.org, typo3.org, my.typo3.org)
2. Go to t3olayout extension
3. git checkout develop
4. git checkout update-gulp-and-fix-security-issues-in-packages
5. Test the website if there are icon issues