Fixing Errors in ImageData utility class that made readout of a qmini point spectrum not possible (#88)

* fixing broken qmini readout

* update cube_utils documentation + unit tests

* update version to ship hotfix

* fix: guard of spectrum accessor

Author: birkholz-cubert

cuvis/Measurement.py

@@ -125,7 +125,11 @@ def refresh(self) -> None:
                                                                 key, info)
                 self.data.update({key: SensorInfo._from_internal(info)})
             else:
-                self.data.update({key: "Not Implemented!"})
+                # The C API reports entries it cannot hand out with an empty key,
+                # so they need a distinct one here or they overwrite each other.
+                self.data.update(
+                    {key or "unsupported_data_{}_{}".format(cdtype, ind):
+                        "Not Implemented!"})
 
     def save(self, saveargs: SaveArgs) -> None:
         ge, sa = saveargs._get_internal()