algo: Unpack TOF and STS in parallel.

Backports work done by our Master Student Sebastian Heinemann to unpack MS in parallel. I made additional changes to unpack the entire timeslice instead of individual components in parallel and generalized it, so this scheme can be easily applied to other detectors as well. However this requires changes to the Unpacker algorithm, to ensure they are thread-safe. As a proof of concept, it's currently applied to STS and TOF.

Note: requires MR !1201 (merged).

cc: @d.smith