These methods are only used by nsNavHistoryResult so it doesn't make sense to have them in the Bookmarks service.
Long term (after tags are converted) the Bookmarks service should be merged into renamed nsNavHistory anyway.

Methods that need a db connection can be moved into nsNavHistory, others into nsNavHistoryResult... we can eval.

Code renames/cleanups are welcome while doing this.

Moving ResultNodeForContainer to nsNavHistory would also be fine, along with the GUID version of FetchItemInfo() that is only used there.