(#20584) Add acceptance test for safer yaml handling in request body

This test uses the handling of report data as a proxy for all payload yaml
handling. It assumes that if we have safe yaml handling in one endpoint, that
the others will also be using the same code paths for deserialization and
therefore be patched correctly.
(#20584) Add acceptance test for safer yaml handling in query parameters

As in the previous commit this adds an acceptance test to make sure arbitrary
objects are not loaded from YAML. This tests input via query parameters, which
uses a different code path from YAML submitted in the body of a request.
Merge pull request #2395 from haus/maint/2.7.x/pup_208_add_acceptance_tests

(PUP-208) Merge acceptance tests from CVE-2013-3567 upstream