Add parsers

[vdbaan]

Add pasers for the following tools:

• Burp
• ZAP
• Nexpose
• OpenVAS

Add test files for all.

[davevs]

I'd like a parser for arachni too is it's easier to fully automate with cli and allows for remote initiation making it a better fit for ci/cd than zap or burp.

[vdbaan]

Burp - Done
ZAP - Initial version