Replaces smileys and the logic of replacing links/emails. (#3560)
* Replaces smileys and the logic of replacing links/emails.
Now using react-emoji-render and react-linkify.
* Fixes heart emoji.
It is known that current implementation doesn't work with ascii emojis that contain < or >, like >:( >:-( </3 <\3 <3. Making those work may bring some xss issues.
* Adds '_blank' and 'noopener noreferrer' to the replaced links.
* Fixes package-lock links (http vs https).
* Fixes comments.