LoadEventNexus fails if a bank name is specified that has no events in it

[Russell Taylor]

​This commit led to the regression. If an empty bank is given then you are given back an error message like:

Error in execution of algorithm Load: No entry named 'bank9' was found in the .NXS file.

Bank 9 of VIS_2570.nxs.h5 is an example of this.

The fix is simple (I think), but a test should also be added to prevent re-regression.

[Russell Taylor]

Bank10 of HYSA_12509.nxs.h5 (in AutoTestData) is an empty bank that can be used for the test.

[Russell Taylor]

Re #8613. Add a test that exposes the bug.

Changeset: f0c73dc430c628c664c80fe80ae558ac3e15db3c

[Russell Taylor]

Re #8613. Remove code that bails out early if no events in a bank.

We need the bank name to be added to the list even if it's empty as it's checked for if the BankNames property has been set. There's already a check that means that no LoadBankFromDiskTask is created for the bank if it's empty (the original justification for adding this code in commit [36540217]).

I don't think this change has much other effect, but I'll be relying heavily on the tests to confirm that given the horrific complexity of the file.

Changeset: 27cfa2098f557a1dbeac4a40075915838de3a59d

[Russell Taylor]

In and out of this horrible algorithm as minimally as possible. Just check that all tests, including the new one, are passing.

[Michael Reuter]

Merge remote-tracking branch 'origin/feature/8613_loadeventnexus_empty_bank_failure'

Full changeset: ​0aac32da09fda07d61e574876d466484e7896db3

[Stuart Campbell]

This ticket has been transferred to github issue ​9457