insights: always look up revisions from execution plan, and adds debu…

Created by: coury-clark

This PR does 2 things:

1. Always look up the revision from a compressed execution plan. This is a partial mitigation to the problem where we are seeing invalid revisions appear in the commit index. This doesn't fully solve the problem, because the compression algorithm is still taking these bad revisions into account, but at least the search queries will not fail in this case.
2. Introduce some new temporary debug fields in the commit index - this should help us have a bit more context about what the commits are when they do show up.