This adds some tricks for running truth derivations on AODs, to check what outputs are being requested. If only various kinds of truth derivations are being requested, then we can short-cut a lot of the standard reconstruction setup and drop things like conditions, geometry, etc. Makes the jobs a bit lighter.
Looks like this saves about 1.1GB of memory in the jobs. Doesn't make them run much faster, since most of the additions were null-ops or wastes. As far as I can tell, no change to standard derivation jobs.
This is mostly a sweep by hand from something that was in 21.2 already.