Breaking: #92238 - Service injection in Extbase validators 

See forge#92238

Description 

With the deprecation and removal of objectManager usage in TYPO3, Extbase does not use the objectManager to create validator instances any more.

Impact 

Validators that use dependency injection will experience non injected services for affected properties.

Affected Installations 

All installations that use dependency injection in Extbase validators.

Migration 

Instead of injecting services to the validator, use GeneralUtility::makeInstance to create an instance of required services.

Given the following example for a service injection in a validator:

/**
 * @var ConfigurationManagerInterface
 */
protected $configurationManager;

/**
 * @param ConfigurationManagerInterface $configurationManager
 */
public function injectConfigurationManager(ConfigurationManagerInterface $configurationManager)
{
    $this->configurationManager = $configurationManager;
}
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Since the configurationManager is required globally in the class, GeneralUtility::makeInstance is used in the constructor of the validator to create an instance of the service.

/**
 * @var ConfigurationManagerInterface
 */
protected $configurationManager;

public function __construct(array $options = [])
{
    $this->configurationManager = GeneralUtility::makeInstance(ConfigurationManagerInterface::class);
    parent::__construct($options);
}
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In order to create instances of services that require dependency injection and which are not already instantiated in the service container, it is required to declare those services as public: true in the Configuration/Services.yaml of the given extension.

Vendor\MyExtension\Services\MyService:
  public: true
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