beamtracker: ID16A cradle correction

Closes #239 (closed)

The cradle correction is a specific correction due to the ID16A mechanic.

This PR rework a but the BeamTracker eand create such correction for ID16A in a derived class.

• Created compute_corrected_position, to compute the absolute resulting position of the motors
• Created tomo.beamline.ID16A.id16a_beam_tracker.ID16ABeamTracker to handle specific mechanic correction

This change have to be propagated to the sxbeam controller of ID16A, else the cradle correction will not be applied.

FYI @pguillou

ID16ABeamTracker

The dedicated beam tracker have to be configured the following way:

        - name: tomo_beam_tracker
            plugin: generic
            class: ID16ABeamTracker
            package: tomo.beamline.ID16A.id16a_beam_tracker

            # Radius of the cradle, in mm
            cradle_r: 103.17
            # Position of the center of the cradle, in the y-axis
            cradle_sy_origin: -1.93208
            # If true, the correction is applied
            correct_cradle: true

In BLISS, this is also displayed as part of the info.

ID16ABeamTracker: test_beam_tracker__beam_tracker

          Angle        Displacement/meter
--------  -----------  --------------------
sy_angle  0.0000 rad   0.000000 mm
sz_angle  0.0000 rad   0.000000 mm

Cradle
------
active    True
r         103.1700 mm
sy_orig   -1.9321 mm