want completed/failed sagas in mainline OMDB

IMDB is very useful if you would like to view information about completed sagas (such as Star Wars, a saga which completed in 1983 with the release of Return of the Jedi). Unlike IMDB, OMDB can currently only show a list of sagas which are running, using omdb db sagas active. If one would like to see a list of sagas which have run to completion or have unwound, one must use omdb-saga, a special binary which (as far as I know) basically exists only on @jmpesp's computer.

We should upstream this functionality into the normal omdb binary. Now that it has a version of omdb saga show, listing completed and unwound sagas is the only remaining task that one must still track down a copy of omdb-saga in order to perform.

Start by tracing the existing omdb db sagas active and omdb saga show commands in the normal omdb binary. Compare their handling with the completed and unwound saga functionality in omdb-saga, if that binary's implementation is available. Done means the normal omdb binary can list running, completed, and unwound sagas without requiring omdb-saga.