Change the seeding input and output, and rework hit flagging

Goes together with Moore!771 (merged) and Brunel!1138 (merged) and Brunel!1158 (merged)

• Changes the input of the seeding to PrSciFiHits, and the output to usual Pr::Seed::Tracks.
• Geometrical information is precalculated and put into a ZoneCache
• Removes parabolic option
• Changes ModPrHit to only a fullDex and a coordinate
• Externalises the link between a ModPrHit and its index in the hit handler (only needed when flagging)
• Quasi-entirely remove hit flagging, choose to rebuild the hit handler at the end of each case.

To-do:

• put the ZoneCache into a nameless namespace

• make the related Moore MR

Previous Valgrind (890M calls):

Current Valgrind (778M calls)

@sstahl @decianm