Indicate missed shadow points in tube re #6728

When not all points are used for calibration, the ordinal number of missed points are now printed.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Adjusted expected positions in WISH example re #6728

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Add an example with wide margins re #6728

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>