[BUG] [Symfony] Backslashes in namespaces passed to the Assert\Type ctor are not escaped

Created by: nicolas-girod

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix ([example]

Description

Version 4.3.0

If any part of the namespace of a type starts with an escape character, the string is mangled (contains a unicode or non-printable character) when passed to the constructor to Assert\Type.

Generated code for the controller with "invokerPackage": "Api\\v1" in the configuration file:

        // Deserialize the input values that needs it
        try {
            $body = $this->deserialize($body, 'Api\v1\Model\MyType', $inputFormat);
        } catch (SerializerRuntimeException $exception) {
            return $this->createBadRequestResponse($exception->getMessage());
        }

        // Validate the input values
        $asserts = [];
>>>     $asserts[] = new Assert\Type("Api\v1\Model\MyType");
        $asserts[] = new Assert\Valid();
        $response = $this->validate($body, $asserts);

Here \v is converted to the vertical tab character.

Suggest a fix

Escape the backslashes or use single quotes for the string passed to the constructor of Assert\Type