Add coder as a dev requirement

Let's add this to the template and also update existing projects:

    "require-dev": {
        "dealerdirect/phpcodesniffer-composer-installer": "^0.4.3",
        "drupal/coder": "^8.2"
    }

In addition to that, att dealerdirect/qa-tools as soon as the conflict with Drush 9 got resolved.