Prepare for integration of CPL recipes
Several improvements necessary for the integration of CPL recipes:
- Add support for uncertainty and quality FITS extensions.
- Make DO.CATG values shorter and include them in the FITS files.
- Remove the three different filenames and settle on a single short filename (so it can be included in the FITS headers). Also remove the symlinking.
- Implement McdDetPersistence, and improve McdDetDark