Drop dependency on scipy

[grzanka]

In the converter code scipy library is used to handle rotation matrix calculations,
see:

• converter/converter/shieldhit/geo.py

  Line 5 in b5326df

  from scipy.spatial.transform import Rotation as R

  and

  converter/converter/shieldhit/geo.py

  Line 39 in b5326df

  rotation = R.from_euler('xyz', box.rotation, degrees=True)

• converter/converter/fluka/helper_parsers/figure_parser.py

  Line 4 in b5326df

  from scipy.spatial.transform import Rotation as R

  and

  converter/converter/fluka/helper_parsers/figure_parser.py

  Line 73 in b5326df

  rotation = R.from_euler('xyz', cylinder.rotation, degrees=True)

By replacing this code with pure python solution we could drop scipy from requirements which would make it more easier to ship with pyodide.

See also #191 (comment)