Remove Hardcoding from Raman Reader

[RonHildebrandt]

According to @lukaspie suggestion

Just a general note here: this CONVERT_DICT will be problematic in the long run once you have files from different detectors/samples because you are essentially hardcoding their name here. You could simpy write detector_TYPE[detector_DU970BV] in your ELN and skip the replacement here (or just use generic "Detector": "detector_TYPE[detector]").