Eliminate HelperSet usage in console-related code

[Majkl578]

Feature Request

Q	A
RFC	yes
BC Break	yes

Summary

Depending on whether symfony/symfony#27647 gets merged into Symfony 4.2 or not, HelperSet may become deprecated.

This would affect all Migrations console commands as the HelperSet is used quite extensively:

• migrations/lib/Doctrine/Migrations/Tools/Console/ConsoleRunner.php

  Line 32 in ba84e1e

  public static function run(HelperSet $helperSet, array $commands = []) : void

• migrations/lib/Doctrine/Migrations/Tools/Console/ConnectionLoader.php

  Line 47 in bba2123

  HelperSet $helperSet

• migrations/lib/Doctrine/Migrations/Tools/Console/Command/AbstractCommand.php

  Lines 175 to 199 in f392a2b

  	private function hasConfigurationHelper() : bool
  	{
  	/** @var HelperSet|null $helperSet */
  	$helperSet = $this->getHelperSet();
  	if ($helperSet === null) {
  	return false;
  	}
  	if (! $helperSet->has('configuration')) {
  	return false;
  	}
  	return $helperSet->get('configuration') instanceof ConfigurationHelperInterface;
  	}
  	private function getConnection(InputInterface $input) : Connection
  	{
  	if ($this->connection === null) {
  	$this->connection = (new ConnectionLoader($this->configuration))
  	->getConnection($input, $this->getHelperSet());
  	}
  	return $this->connection;
  	}

• migrations/lib/Doctrine/Migrations/Configuration/Connection/Loader/ConnectionHelperLoader.php

  Lines 22 to 51 in ba84e1e

  	/** @var HelperSet */
  	private $helperSet;
  	public function __construct(?HelperSet $helperSet = null, string $helperName)
  	{
  	$this->helperName = $helperName;
  	if ($helperSet === null) {
  	$helperSet = new HelperSet();
  	}
  	$this->helperSet = $helperSet;
  	}
  	/**
  	* Read the input and return a Configuration, returns null if the config
  	* is not supported.
  	*/
  	public function chosen() : ?Connection
  	{
  	if ($this->helperSet->has($this->helperName)) {
  	$connectionHelper = $this->helperSet->get($this->helperName);
  	if ($connectionHelper instanceof ConnectionHelper) {
  	return $connectionHelper->getConnection();
  	}
  	}
  	return null;
  	}

• migrations/bin/doctrine-migrations.php

  Lines 65 to 91 in 08aba2a

  	$helperSet = null;
  	if ($configurationFile !== null) {
  	if (! is_readable($configurationFile)) {
  	trigger_error('Configuration file [' . $configurationFile . '] does not have read permission.', E_USER_ERROR);
  	exit(1);
  	}
  	$helperSet = require $configurationFile;
  	if (! $helperSet instanceof HelperSet) {
  	foreach ($GLOBALS as $helperSetCandidate) {
  	if (! $helperSetCandidate instanceof HelperSet) {
  	continue;
  	}
  	$helperSet = $helperSetCandidate;
  	break;
  	}
  	}
  	}
  	$helperSet = $helperSet ?? new HelperSet();
  	$helperSet->set(new QuestionHelper(), 'question');
  	$commands = [];
  	ConsoleRunner::run($helperSet, $commands);

Even if the referenced deprecation doesn't make it into 4.2/4.x, it'd still be a good idea to do this change before 2.0 GA.

[goetas]

#898 should address this

[goetas]

done in #898