Imports of package discovery

PathSynopsis
github.com/open-policy-agent/opa/pluginsDeprecated: This package is intended for older projects transitioning from OPA v0.x and will remain for the lifetime of OPA v1.x, but its use is not recommended.
github.com/open-policy-agent/opa/v1/hooks
github.com/open-policy-agent/opa/v1/metricsPackage metrics contains helpers for performance metric management inside the policy engine.
github.com/open-policy-agent/opa/v1/plugins/discoveryPackage discovery implements configuration discovery.