Create routine that generates csv for Dicom ECG metadata configuration
As in the xnat desktop application, the user should be able to customize the metadata of each ecg (e.g. SubjectID and SessionID). To do this, it is necessary to generate a csv based on the ecgs in the folder. First it has to be checked if the IDs match the xnat rules for IDs (only characters, digits and "_") and then the csv should be generated. Then the csv has to be read again and the program should use this metadata to upload the ecgs to xnat.