Returns a data frame (tibble) containing columns with node ID,
node identifier (name), number of properties associated with that
node and a summary of the values for that node.
Details
Note: IDs are a thing internal to this R package. They are not imported
from or exported to actual ISA-tab files. However, given that the node
'identifiers' (e.g. 'Sample Name') can be ambiguous, IDs are necessary
to unambiguously identify a node.