Echo to json_encode

[davideC00]

• [X] I've read and understood the contribution guidelines.
• [X] I've searched for any related issues and avoided creating a duplicate issue.

Please give us a description of what happened.

Now, for printing json metadata to html, each plugin use the function echo.

Using this approach leads to:

• More work because you need to format manually the metatags
• Difficulties in maintainance of the code
• Secure issues
• Parsing errors

Describe the solution you'd like

1. There is a single array passed to each plugin
2. Each plugin adds their metadata to it
3. The array is printed with json_encode

   
   printf( '<script type="application/ld+json">%s</script>', json_encode( $array, JSON_PRETTY_PRINT) );

 json_encode format the metatags automatically with JSON_PRETTY_PRINT.
this is a common solution used by others plugin like Pressbook, Framework Seo ecc...

[davideC00]

Solved 7e52ae4ecdc91e28c604a1be0dd8278ae4676c59