better debug when setting/getting the SPB2 (HD) config
* Added FrelonAcq.set/getSPB2Config for a full camera control
* Added persistent Frelon::Camera m_roi_bin_offset,
  set in setRoiBinOffset and taken into account in setRoi;
  it is reset when changing the binning or disabling the roi
* Better max. parameter checking in Frelon::Camera::setBin