Add task to sum images of a single bliss scan
After a bit of thinking, I realized a lot of inputs of SumImages
did not make sense when wanting to sum a single bliss scan.
So similarly to Integrate
tasks, I made a simple task SumBlissScanImages
rather than extending the existing SumImages
task. Also for the future, I think it will be easier to merge the tasks than to disentangle a single complex task if needed.