Pass Child Estimated Time if Final re #3762

Passing the unmodified estimated time of a child algorithm that finishes when its parent finishes,
fixes this ticket for the use case of SANS2D00005512.nxs described in this ticket.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Put Functional Form into Ideal Tube re #6343

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Reverse change cos of side effect in SaveNexus re #3762

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Replaced two function with getPoints() re #6343

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Tidy up demo programs re #6343

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