Fixed null parameter warning in Mage_Wishlist_Controller_Abstract::allcartAction()

[addison74]

This PR is related to the issue #4076.

I am getting this error with PHP > 8.1 in the system.log file:

Deprecated functionality: strlen(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/html/app/code/core/Mage/Wishlist/Controller/Abstract.php on line 88

/app/code/core/Mage/Wishlist/Controller/Abstract.php on line 88

In order to reproduce this issue log into a customer account in the Frontend then add any product to the Wishlist. You will be redirected to the customer account. A part of the URL is wishlist/index/index/wishlist_id/[PRODUCT_ID]/. Press the [Add All to the Cart] button. In my case I am getting an error message because the product has custom options and I have to choose them. If you take a look into the /var/log directory you will see a nice system.log file, having 374 kB as size and inside the same line 1745 times. Every line is for a product which is not in the wishlist. With a script someone could make the system.log file as big as he wants, an pretty fast.

IMPORTANT NOTE
This PR has 4 implementations inside (4 lines - 1 my choice, 3 commented), there may be others. Please share your opinions, at the end there will be only one line left. Once it is merged I will fix the same issue in the Import/Export module.

array_filter($VARIABLE, fn ($tmpString) => strlen($tmpString ?? ''))
// $qtys = array_filter($VARIABLE, function ($tmpString) { return strlen($tmpString ?? ''); });
// $qtys = array_filter($VARIABLE, function ($tmpString) { return $tmpString !== NULL && strlen($tmpString); }); => From Drupal Community
// $qtys = @array_filter($VARIABLE, '\strlen');

[fballiano]

tested, works perfectly

[sreichel]

On phpstan level 5 ...

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Line Controller/Abstract.php

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88 Parameter #2 $callback of function array_filter expects (callable(mixed): bool)|null, Closure(mixed): int<0, max> given.

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