[WIP] [HttpKernel] Fixed cache behavior when TTL has expired

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | no
| Related tickets | #8232, #10822
| License       | MIT

- [ ] gather feedback for test when TTL has expired
- [ ] try to fix it if tests are correct by fixing the [default TTL configuration][0]

When the cache is stale the `validate` method `forward` the request to the backend. A new response will be created with or without TTL configuration. If the TTL was not set then the default one should be set like in the `fetch` method.

[0]: https://github.com/alquerci/symfony/blob/6d2dcbf3824742bdbf00830d77644e50d733ae77/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php#L435