Add to settings custom nonce function

Hi there,

In my WP plugin, I just added a custom function that checks the nonce:

	/**
	 * Validate nonce
	 *
	 * @param string $nonce_action Action for nonce
	 * @param string $nonce_field Field name in $_POST or $_GET
	 * @return bool True if nonce is valid
	 */
	protected function is_valid_nonce( string $nonce_action, string $nonce_field ): bool {
		return isset( $_POST[ $nonce_field ] ) && is_string( $_POST[ $nonce_field ] ) && wp_verify_nonce( sanitize_key( $_POST[ $nonce_field ] ), $nonce_action ) > 0;
	}
}

With PHPCS, i just declared a property customNonceVerificationFunctions, and it is correctly handled.

But with plugin-check-action, I don't know how tho handle this custom function, since in functions using is_valid_nonce(), it triggers WordPress.Security.NonceVerification.Missing warning.

I can obviously avoid the warnings using ignore-codes, but it doesn't seem to me a sustainable solution.

Start by reviewing the plugin-check-action path that invokes PHPCS and the handling of the customNonceVerificationFunctions setting. Trace how functions such as is_valid_nonce() are identified, then define the setting and warning behavior needed so valid custom nonce checks no longer produce WordPress.Security.NonceVerification.Missing warnings.