Fixing a bug in TFCSParametrizationChain

Henry Day-Hall requested to merge hdayhall/athena:less_unique_ptr into 23.0

So when creating param files for the fast simulation we make and write many TFCSParametrizationChain objects to a root file. This was causing a seg fault, coming from the streamer of TFCSParametrizationChain. I asked for help on the root forum, where pcanal gave an excellent explanation; objects owned by m_chain were also being given to a unique_ptr, such that delete was called on the data twice.

I tested this fix by making and running a large param file and it worked.

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