Add fuzzing
Add fuzzing

This is a verbatim copy of github.com/tsandall/fuzz-opa, importing
fuzzing to the main repository.

Updates #1652

Signed-off-by: Yevgeny Pats <5de2bc56b28a5be7cb70ccc2d375e79487bff24e@fuzzit.dev>

open-policy-agent/opa,open-policy-agent/opa,open-policy-agent/opa,open-policy-agent/opa,open-policy-agent/opa,tsandall/opa,tsandall/opa,tsandall/opa,open-policy-agent/opa,tsandall/opa,tsandall/opa,tsandall/opa