account for LTER and EDI datasets in categorize_dataset

[laijasmine]

datasets from LTER and EDI that don't use the DOI in the metadata pid. Make sure to include that in the stopifnot check in the beginning.

[mbjones]

@laijasmine why does categorize_dataset limit itself to only DOI identifiers? That seems unneeded, and limits the utility of datamgmt to specific repositories. Hardcoding the pasta string into a generic library seems problematic. Can't you just remove the restriction altogether?

[laijasmine]

@mbjones you are right. Addressed that in the new commit