create easier dataframe with meta data

[rwaaijman]

All the meta data could be find with get_dataflow_structure(). Would it be more user-friendly is meta data is shown in a dataframe,
for example
get_dataflow_topics(), which shows in a dataframe the id, title, description, unit, ....
get_dataflow_dimensions(), which shows id, title, ...

[edwindj]

This is a difficult one: the current line of thinking is to conform to the SDMX metadata model, which is slightly different from the previous cbsodata meta data model.
In general it is wise to conform to the new standard, otherwise the package will be stuck "in the past".
OTOH, simple often is better...