Write algorithm to tuple extrapolations

This needs to store all information neeed to produce parameteriations of the movement. It should not (necessarily) depend on the velo tracking. Plain MC information using only the RK extrapolator should be sufficient. Use gaudi properties to make specific locations (like the reference plane) configurable.

gaudi properties:

• end of velo position
• reference plane position
• reconstructibility requirements

data handles:

• MCParticles
• velo hits
• scifi hits

tuple:

• velo state (including momentum)
• pid
• scifi hit positions
• fit parameters from internal model (cubic in x, parabolic in y)
• chi2 + dof of the fit (assuming an average weight of the hits)
• dSlope
• true magnet kink z position
• extrapolated states for each layer
• magnet polarity