New thor functors for differents types of covariance matrix

Following the issue #422 (closed)

This MR will add more functors to access different types of covariance matrices and rename the old F.COVARIANCE functor as F.TRACK_COVARIANCE since it just returns the covariance matrix for the track state (x, y, tx, ty, qop).

New functors are:

• F.THREE_MOM_COV_MATRIX: (px, py, pz)
• F.THREE_MOM_POS_COV_MATRIX: (px, py, pz) x (x, y, z)
• F.MOM_POS_COV_MATRIX: (px, py, pz, pe) x (x, y, z)
• F.POS_COV_MATRIX: (x, y, z)

ToDo:

• Test for V2 particles
• Test for V1 particles

FIY: @amathad @pkoppenb @erodrigu