MNT: make shallow copy of dicts before caching
MNT: make shallow copy of dicts before caching

ericdill/databroker,arkilic/metadatastore,NSLS-II/metadatastore,ericdill/databroker,tacaswell/metadataStore,hhslepicka/metadatastore,tacaswell/metadataStore,hhslepicka/metadatastore,arkilic/metadatastore,NSLS-II/metadatastore