Io modification in preparation for Fatras switch

Updates the csv and Root particle and hits writers in preparation for the upcoming switch to the Fatras version in Core. Harmonizes the column/branch names of both writers and extends them. Particles store

particle_id
particle_type
process
vx, vy, vz, vt # production vertex
px, py, pz     # momentum
m              # mass
q              # charge

but not the previously store number of hits.

Simulated (truth) hits store

particle_id
geometry_id
tx, ty, tz, tt    # truth hit position
tpx, tpy, tpz, te # truth particle four-momentum before interaction
deltapx, deltapy, deltapz, deltae # four-momentum change due to interaction
index             # hit index along the particle trajectory

The full encoded geometry identifier is also store for hits/cells (CSV writers).

The new columns do not always contain meaningful data yet. This will be fixed in a future MR.

Standalone generator tools are now prefixed ActsGen as discussed in #175.