Reconciliation of Synced Data

[maxsmythe]

If we want to use freestanding OPA in the future, we will need to periodically reconcile cached constraint/constraint templates to account for the fact that the query engine and its interface may have separate lifecycles.

[maxsmythe]

We should just wipe the OPA cache on restart if we want to support remote (sidecar, etc.) OPA.

[sozercan]

Closing in favor of #704.