ENH: add new DAOS module data to PyDarshan "data access by category" plots

[shanedsnyder]

Currently, "data access by category" plots just show aggregate file and byte counts for various mount points accessed by an application.

We should try to extend/generalize this plot to accomodate DAOS data, probably adding new rows for each DAOS pool/container accessed by the app (in addition to traditional POSIX file system mount points).