Feature/rotate part of model

[VonKanelF]

Task: Add option in the rotation step to twist/rotate part of the model.
Solution found: Create a lattice adjusted to the size of the uFit object and use a lattice modifier to rotate part of the model.

Notes on the choices made:

• Only small rotations are allowed as this modifier does not preserve volumes, it can be adjusted with the strength parameter.
• The size of the lattice grid is controlled with the grid_factor parameter, it can be adjusted if necessary.
• The option is activated by checking the box in the panel, and changes are validated by unchecking the box. You cannot proceed to the next step until the changes have been validated.