Remove Livequery from javascript code

[nebojsatomic]

Livequery ( jQuery plugin ) was used for detecting events on dynamically created elements, in 2013, and is now very old and unnecessary. It should be removed and replaced with vanilla JS, in the Admin panel at first, and the rest of the code later.

Also jQuery could be replaced with plain vanilla JS, but that is a much bigger task, requires a lot of effort by removing all the other jQuery plugins, and it will be a separate issue.