Add nonces for inline scripts to CSP

This code works well so far but would be good to figure out some configurability. Also needs a lot of cross browser testing.

```php
add_action( 'template_redirect', function () {

// Collect full page output.
ob_start( function ( $output ) {

$nonces = [];

$output = preg_replace_callback( '##', function ( $matches ) use ( &$nonces ) {
$nonce = wp_create_nonce( $matches[0] );
$nonces[] = $nonce;

return str_replace( '