Fixed XSS vulns in deserialization testfiles

[Mike-Ki]

Summary

This PR contains two commits addressing XSS issues in the deserialization test suite.

Commit 1: Fix XSS vulns in deserialization testfiles

Fixes 11 reflected XSS vulnerabilities in deserialization test cases where
user-controlled input was rendered unescaped in the response.

Commit 2: Escape non-vuln cases to prevent false XSS hits

The remaining non-vulnerable deserialization test cases were escaping output
to ensure they are not incorrectly flagged as XSS vulnerabilities. These
cases are intended for deserialization coverage only.

---

PoCs

BenchmarkTest00079.py

POST /benchmark/deserialization-00/BenchmarkTest00079 HTTP/1.1
Host: 127.0.0.1:5000
Cookie: BenchmarkTest00079=text%3A+%3Cscript%3Ealert(1)%3C%2Fscript%3E

BenchmarkTest00269.py

POST /benchmark/deserialization-00/BenchmarkTest00269 HTTP/1.1
Host: 127.0.0.1:5000
Content-Type: application/x-www-form-urlencoded

BenchmarkTest00269=text%3A+%3Cscript%3Ealert(1)%3C%2Fscript%3E

BenchmarkTest00270.py

POST /benchmark/deserialization-00/BenchmarkTest00270 HTTP/1.1
Host: 127.0.0.1:5000
Content-Type: application/x-www-form-urlencoded

BenchmarkTest00270=text%3A+%3Cscript%3Ealert(1)%3C%2Fscript%3E

BenchmarkTest00271.py

POST /benchmark/deserialization-00/BenchmarkTest00271 HTTP/1.1
Host: 127.0.0.1:5000
Content-Type: application/x-www-form-urlencoded

BenchmarkTest00271=text%3A+%3Cscript%3Ealert(1)%3C%2Fscript%3E

BenchmarkTest00434.py

POST /benchmark/deserialization-00/BenchmarkTest00433 HTTP/1.1
Host: 127.0.0.1:5000
Content-Type: application/x-www-form-urlencoded

text%3A+%3Cscript%3Ealert(1)%3C%2Fscript%3E=BenchmarkTest00433

BenchmarkTest00435.py

POST /benchmark/deserialization-00/BenchmarkTest00435 HTTP/1.1
Host: 127.0.0.1:5000
Content-Type: application/x-www-form-urlencoded

%7B%22text%22%3A%22%3Cscript%3Ealert(1)%3C%2Fscript%3E%22%7D=BenchmarkTest00435

BenchmarkTest00827.py

GET /benchmark/deserialization-00/BenchmarkTest00827?BenchmarkTest00827=text%3A+%3Cscript%3Ealert(1)%3C%2Fscript%3E HTTP/1.1
Host: 127.0.0.1:5000

BenchmarkTest00828.py

POST /benchmark/deserialization-00/BenchmarkTest00828?BenchmarkTest00828=%7B%22text%22%3A%22%3Cscript%3Ealert(1)%3C%2Fscript%3E%22%7D HTTP/1.1
Host: 127.0.0.1:5000

BenchmarkTest00904.py

POST /benchmark/deserialization-00/BenchmarkTest00904?BenchmarkTest00904=%7B%22text%22%3A%22%3Cscript%3Ealert(1)%3C%2Fscript%3E%22%7D HTTP/1.1
Host: 127.0.0.1:5000

BenchmarkTest00994.py

POST /benchmark/deserialization-00/BenchmarkTest00994?BenchmarkTest00994=text%3A+%3Cscript%3Ealert(1)%3C%2Fscript%3E HTTP/1.1
Host: 127.0.0.1:5000

BenchmarkTest00998.py

POST /benchmark/deserialization-00/BenchmarkTest00998?BenchmarkTest00998=%7B%22text%22%3A%22%3Cscript%3Ealert(1)%3C%2Fscript%3E%22%7D HTTP/1.1
Host: 127.0.0.1:5000