(Snyk) Fixed finding: "Improper Neutralization of CRLF Sequences in HTTP Headers" (#3424)

## Remediation

This change fixes "Improper Neutralization of CRLF Sequences in HTTP
Headers" (id = java/HttpResponseSplitting) identified by Snyk.

## Details

This change ensures that HTTP response header values can't contain
newline characters, leaving you vulnerable to HTTP response splitting
and other attacks.

If malicious users can get newline characters into an HTTP response
header, they can inject and forge new header values that look like they
came from the server, and trick web gateways, proxies, and browsers.
This leads to vulnerabilities like Cross-site Scripting (XSS), HTTP
response splitting, and more attacks from there.

Our change simply makes sure that if the string passed to be a new
response header value is non-null, all the newline characters (CR and
LF) will be removed:
```diff
+ import io.github.pixee.security.Newlines;
  ...
  String orderId = getUserOrderId();
- response.setHeader("X-Acme-Order-ID", orderId);
+ response.setHeader("X-Acme-Order-ID", Newlines.stripAll(orderId));
```

Note: Many modern application servers will sanitize these values, but
it's almost never specified in documentation, and thus there is little
guarantee against regression. Given that, we still recommend this
practice.

<details>
  <summary>More reading</summary>

*
[https://cwe.mitre.org/data/definitions/113](https://cwe.mitre.org/data/definitions/113)
*
[https://www.netsparker.com/blog/web-security/crlf-http-header/](https://www.netsparker.com/blog/web-security/crlf-http-header/)
*
[https://owasp.org/www-community/attacks/HTTP_Response_Splitting](https://owasp.org/www-community/attacks/HTTP_Response_Splitting)
*
[https://regilero.github.io/security/english/2015/10/04/http_smuggling_in_2015_part_one/](https://regilero.github.io/security/english/2015/10/04/http_smuggling_in_2015_part_one/)
</details>

Co-authored-by: pixeebot[bot] <104101892+pixeebot[bot]@users.noreply.github.com>