tomography detectorClass addition

The list of detectorTypes in the SEM FIB Tomography dataset schema is quite long and resembles the vendor specific naming of detectors. While this allows for easy and transparent extraction, some of the values provided there can be counted as the same 'class' as far as I understand. This could be valuable additional info especially for unified analysis.

Suggestion: add an optional detectorClass enum that can either be filled manually after extraction or be auto created in case of a provided mapping between vendor specific name and more generic 'class'.

Domain expert information is needed for both the class enum and an initial mapping based on existing values in the detectorType.

(additional discussion point: The detectorType in the SEM schema is not a fixed list, not sure if both approaches should be more comparable in that regard)

The issue names no file, test, or entry point to inspect. Begin by reviewing the SEM FIB Tomography dataset schema and its existing detectorType values, then consult materials-science domain experts to define the detectorClass enum and vendor-to-class mapping; completion requires agreement on those definitions and the optional field's treatment.

Written by the indexing model from the issue text.