Using MultiValueEnum for MCMICRO

[melonora]

In some cases, there are multiple directories for which it contents needs to be parsed using a specific model. For example, the directory 'registration', 'dearray' and 'probability_maps' all contain images and should be parsed with the spatialdata ImageModel. Currently, the ModeEnum is not able to handle this. An alternative could be the MultiValueEnum which is part of the aenum library.

Currently this would lead to a metadata conflict, but I think it should be considered as otherwise it is not possible to handle enums with multiple values.

[LucaMarconato]

Thanks for the info. I think it would be a good solution indeed!