China Video Block

Fixes PHP Notice "Trying to access array offset on value of type bool" WordPress 5.8 compatibility

• loads the front-end script using wp_enqueue_script() only when the block is present on the page

• fixed the ver number on the script so that the block doesn't keep breaking

• added a browser-busting version querystring for the front.js file so that browsers download the new file when it updates

• added compiled build file

• rewrite of the code to favor the China video; the problem was that, when favoring the non-China video, it would produce a failed request for users in China since it was loaded on page load before being changed to the China video
• when the ipinfo call produces and error, no cookie value is now set so that the call can be tried again during a subsequent page load