Expose entry-type and migrate-entries for RedisActionCache
Description
The Redis Action Cache has support for storing either the ActionResult digest to save space, or the ActionResult itself to reduce the number of trips to CAS. However you can't actually set the configuration needed to adjust these settings. This PR updates the parser to expose these options, which already exist and have tests.
Validation
Bring up a BuildGrid with a Redis AC and verify these options can now be set.