Update load.php with wp_is_bad_request function

[rpayne7264]

I propose adding a wp_is_bad_request function to load.php, as a way to allow plugin developers to short circuit code execution if the HTTP request that started the WordPress load process is considered a junk request. See: #17246

The existing wp_favicon_request (renamed to wp_favicon_request_x in test file) is re-written to use the proposed wp_is_bad_request function.

[rpayne7264]

test file for proposed wp_is_bad_request enhancement

[rpayne7264]

For clarification:

When I say short circuit code execution, I mean: short circuit plugin code execution, not short circuit WordPress code execution.

Example:

<?php 

class RDP_PLUGIN {
        private static $_instance = NULL;

        private function __construct() {
            // prevent running code unnecessarily
            if(wp_is_bad_request())return;
            
            // run the plugin
            add_action('wp_loaded',array( $this, 'run'),1);             
        }//__construct
            

        public static function get_instance(){
            if (NULL === self::$_instance) self::$_instance = new self();
            return self::$_instance;
        } //get_instance 
                
                ...  other plugin code ...

}

$RDP_PLUGIN = RDP_PLUGIN::get_instance();

[rpayne7264]

revised wp_is_bad_request() & added test cases

[rpayne7264]

Removed 'ico' param in wp_favicon_request_x() code

[rpayne7264]

After nearly one year, and still no movement on this. Bummer!