Library Profile: We need some objects for the LibraryUseEvent.

We need identifiers for the LibraryUseEvent, which is about being in the library to do something that may or may not be directly related to a library participation or resource usage.  I think those things include a location (main library, branch library, law library...), a sub-location (learning commons, study room, makerspace...), and a time/date stamp.
