(io): increase the DICOM services log level

Description

Add detailed logs for our communications with the PACS.

Closes #610 (closed)

How to test it?

• Launch OgreViewer.
• Click on the second button : Open PACS.
• Now you can retrieve DicomSeries from the PACS, preview them, and pull the it to an ImageSeries.
• Check new INFO in the SLM file.