Handle invalid JSON body payload sources

[marksmith]

This change handles invalid JSON body payload sources, not extracting body payload sources if the JSON-encoded body could not be parsed. This prevents an ActionDispatch::Http::Parameters::ParseError from being raised and propagating, causing the Aikido::Zen::Middleware::RequestTracker and Aikido::Zen::Middleware::AttackWaveProtector middleware to fail after the application has already processed the request.

The susceptibility of other payload sources has been investigated and discussed internally.

Summary by Aikido

Security Issues: 0	Quality Issues: 0	Resolved Issues: 0

🔧 Refactors

• Ignored invalid JSON body payload sources and added test coverage

^{More info}

[hansott]

maybe safer to put the other calls also in the begin ... rescue block? (req.path_parameters, ...)