Start decoupling error handling from frameworks (#1673)
Start decoupling error handling from frameworks (#1673)

I'm moving frameworks to no longer use the Errors type so that:

1) Errors are printed deterministically
2) Specific errors may be expected in tests
3) We can safely use errors.Is to cut down on boilerplate in error
definitions

I'd like to remove it, but gatekeeper relies on it to concatenate error
messages together. So, I've moved the logic to the one place Gatekeeper
uses the Errors type.

Signed-off-by: Will Beason <53cb3768767fe8a256eb397d8173de4b3cb941dd@google.com>
open-policy-agent/gatekeeper,open-policy-agent/gatekeeper,open-policy-agent/gatekeeper,open-policy-agent/gatekeeper,open-policy-agent/gatekeeper