Extend unit test to test WorkspacesForBanks re #8404

In the course of this,
I relaxed the #workspaces = #banks requirement
whenever WorkspacesForBanks is used.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>
Attempt to fix compiler warning in getProfNumber re #8404

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