Add Sprucing support, prototype lines and tests

Needs LHCb!2965 (merged)

Work towards a Sprucing appplication for run 3, see DPA task https://gitlab.cern.ch/lhcb-dpa/project/-/issues/87.

The location of HLT2 vs. Sprucing lines needs to be concretely defined and is discussed in issue https://gitlab.cern.ch/lhcb-dpa/project/-/issues/81. There will be a dedicated discussion on this in https://indico.cern.ch/event/982563/

This MR adds 4 new qmt tests. We want to test

• Running an inclusive HLT2 line with persistreco (we use the [2,3]body TOPO lines) then
• Running an exclusive Sprucing line (we use the BdToDsmK_DsmToHHH_sprucing_line line from B2OC) on this HLT2 output

We test the case where the original reconstruction is "from_file" (Brunel) and where the reconstruction is done in "real time". (The sprucing test of course should be agnostic to the original reconstruction but I also think these are good tests of the persistency, (de-)serialisation and (un-)packing)