Follow Sigima: image profiles in physical coordinates #436

Sigima now defines image profiles (line, segment, average, radial) in physical coordinates (DataLab-Platform/Sigima#93, DataLab-Platform/Sigima#98): parameters are renamed (row/col → y/x, row1..col2 → x1, y1, x2, y2, x0/y0 → xc/yc) and their contracts move to version 2.

DataLab must follow:

• the profile extraction dialog converts the drawn shapes to pixel indices (physical_to_indices) and back: it must pass physical coordinates directly;
• the last profile position must still be reused as initial shape (Sigima now centers new line/segment parameters on the image with update_from_obj);
• tests use the former parameter names; the cross-edition families reference files record line_profile in contract version 1, now refused instead of replayed;
• the documentation describes the radial center "in pixels".