Reconstruct tags & optionally files of study

Reconstruct the main DICOM tags in DB of the study whose Orthanc identifier is provided in the URL. This is useful if child studies/series/instances have inconsistent values for higher-level tags, in order to force Orthanc to use the value from the resource of interest. Beware that this is a time-consuming operation, as all the children DICOM instances will be parsed again, and the Orthanc index will be updated accordingly.