Digitization for the TOF3

[GiorgioAlbertoLucia]

@njacazio
First steps towards a full digitization for TOF3

• GeometryTGeo class added, to move from the global coordinates to the local coordinate of a given chip
• Segmentation class added, which finds the pixel position (row, col) on a chip, from the local chip coordinate
• Digitizer class further developed, to process single hits and produce digits. Currently a flat efficiency and no checks on the created charge are considered