Add missing 'use' statements for argument types

[schmengler]

This fixes two warnings on startup

PHP Warning: Declaration of TiB\PatchPal\Magento\Command\AbstractCommand::execute(TiB\PatchPal\Magento\Command\InputInterface $input, TiB\PatchPal\Magento\Command\OutputInterface $output) should be compatible with Symfony\Component\Console\Command\Command::execute(Symfony\Component\Console\Input\InputInterface $input, Symfony\Component\Console\Output\OutputInterface $output) in /[...]/.modman/pocallaghan_magerun-patchpal/src/Magento/Command/AbstractCommand.php on line 121

PHP Warning: Declaration of TiB\PatchPal\Magento\Command\CompatCommand::execute(Symfony\Component\Console\Input\InputInterface $input, Symfony\Component\Console\Output\OutputInterface $output) should be compatible with TiB\PatchPal\Magento\Command\AbstractCommand::execute(TiB\PatchPal\Magento\Command\InputInterface $input, TiB\PatchPal\Magento\Command\OutputInterface $output) in /[...]/.modman/pocallaghan_magerun-patchpal/src/Magento/Command/CompatCommand.php on line 12

as well as a fatal error

PHP Fatal error: Uncaught TypeError: Argument 1 passed to TiB\PatchPal\Magento\Command\AbstractCommand::validateChangesetSource() must be an instance of TiB\PatchPal\Magento\Command\InputInterface, instance of Symfony\Component\Console\Input\ArgvInput given, called in /[...]/.modman/pocallaghan_magerun-patchpal/src/Magento/Command/CompatCommand.php on line 32 and defined in /[...]/.modman/pocallaghan_magerun-patchpal/src/Magento/Command/AbstractCommand.php:45

(with PHP 7.1 and Symfony console 3.4.11)