Convert uasort to array_multisort in \Drupal\Core\Plugin\CategorizingPluginManagerTrait::getSortedDefinitions()

Problem/Motivation

Due to a PHP bug (https://bugs.php.net/bug.php?id=50688), uasort is unsafe to use in many circumstances

See #2762549: Drupal\field\Tests\Update\FieldUpdateTest, Drupal\views\Tests\Update\EntityViewsDataUpdateTest and Drupal\comment\Tests\CommentFieldsTest fail on 8.1.x for an example.

Proposed resolution

Convert to using array_multisort().

Remaining tasks

Decide if this needs to be done since The PHP bug #5068 Using exceptions inside usort() callback function causes a warning is fixed in PHP 7.

User interface changes

API changes

Data model changes