CMOVE from long term archive

[toskrip]

When in proxy environment CFIND report DICOM studies, and CMOVE try to fetch SOP instance for RT modalities in order to read further RT related tags to be reported via JSON. The CMOVE fails if reading data from long term archive (there is an actual DICOM error reported from the remote node), because it takes long time to bring the data from the read only slow storage back to online/nearline. As result the lua script also fails.

Need to find a better way of how to present this situation to user. The second call on the same data is then usually successful as the long term archive manages to load what was needed from slow storage to the online/nearline.