bump mapper version to fix zeitwerk problem

[kspurgin]

• eager load collectionspace-mapper to pass zeitwerk:check (as per statement from zeitwerk maintainer)
• Initialize CollectionSpace::Mapper::DataHandler with a client-less RefCache
• Add csid_cache parameter to constructor for CollectionSpace::Mapper::DataHandler -- Since the only way to search for relations is by subject/object CSID, we need a way to efficiently look up CSIDs. Since I'm already setting up collectionspace-mapper to work with two separate CollectionSpace::RefCache instances for migration tooling stuff---one for refnames for terms, and one for CSIDs---it is much more straightforward to just make it always use two separate RefCaches for these two separate types of information. When CollectionSpace::Mapper is used with the default batch config by collectionspace-csv-importer, the CSID RefCache will only be used for looking up CSIDs to use in constructing searches for relations (required to determine the status of a given relation in the system).