Helper to calibrate scintillators

Closes #139 (closed)

• Merge the code from @pautran into tomo.helpers.scintillator_tilt
  • Plus rework for typing and simplification
  • Plus some tests
• Create a scintillator_geometry getter for any optics
  • This can be redefined if needed, but by default it returns the scintillator_geometry key from the yaml config
• Create a focus procedure, from the actual align code
• Use the scintillator_tilt in focus
• Added test coverage for alignxc and focus procedure

Some commits are related to typo or bug fixes, ill also create dedicated PRs to merge them independently to the project.

Description

The scintillator geometry can be described the following way in any optics.

  scintillator_geometry:
    rz:
      screw_distance_mm: 28.65
      screw_pitch_mm: 0.25
      screw_position: "top right"
      orientation: -1
    ry:
      screw_distance_mm: 9
      screw_pitch_mm: 0.25
      screw_position: "bottom left"
      orientation: 1

Alignment with focus

If the geometry description is provided, focus will display such result

Best focus position:         1.0
Tilts vert. and hor. in rad: [-30000. -40000.]

For axis 'ry' (bottom left screw):
 - Displacement Distance: -12.1121 mm
 - 48 full turn(s) and 1 quarter turn(s) and 1 eighth turn(s) and 1 sixteenth turn(s) anticlockwise.
For axis 'rz' (top right screw):
 - Displacement Distance: -84.0651 mm
 - 336 full turn(s) and 1 quarter turn(s) clockwise.
Moving focus_axis from 0.000000 to 1.000000
Focus motor position = 1.0