Added fixtures/test.xml and test_scan_xml.py

[RondoRondoRondo]

Describe the change
Created a test for the xml scanner, 'test_scan_xml.py', with a corresponding test file, 'test.xml'.

Describe testing procedures
Difference test on the expected output of the xml scanner and the output of the test.xml file.
docker-compose -f ./build/docker-compose.yaml build backend

Sample output
No change to Strelka's output.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of and tested my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

[phutelmyer]

Thanks for the PR, @RondoRondoRondo!
I removed the print statement, but looks good + merged.