LoadRaw fails if monitors are not in the file and separate monitor loading is requested.

[Alex Buts]

If one tries to load raw file from run file where the monitors were not written (e.g. LET00015628.raw), and selects load monitors "Separately" the loading fails with confusing error message:

Error in execution of algorithm Load: Workspace2D::getSpectrum, histogram number 65528 out of range 65528

If one tries to load the same file with monitor option "Included", the load succeeds but the workspace naturally does not contain any monitors.

Desired behaviour:

when "separate" option is chosen, main workspace should be loaded successfully and warning message telling that monitors are not present and monitor workspace has not been created should be issued to the user.

[Stuart Campbell]

This ticket has been transferred to github issue ​10265