Add support for Multisite

Hi. That is a great idea to have a plugin like that.

I’ve checked that plugin on my Multisite website, and it seems to have a bug.

The cron job (get_data) updates the options on the main website but the Elementor.php file is loaded on each website. So the get_single_block_list method tries to find the asef_remote_block_list option in his DB table, not on the main website DB table. In that case the blacklist always be empty.

The fix:

    public function get_single_block_list( string $option_name ): array {

        if ( is_multisite() ) {

            switch_to_blog( get_main_site_id() );

        }

        $raw = get_option( $option_name, '' );

        if ( is_multisite() ) {

            restore_current_blog();

        }

        return array_unique( array_filter( array_map( 'trim', explode( "\n", $raw ) ) ) );

    }

Just always get the options from the main website is that is a multisite instance.