return entire SDFITS table row header as a dictionary

[kuiper@…]

asap should store everything in an SDFITS table, even if it doesn't use it. A function like get_scan_header() should return every scientifically meaningful parameter in the table header and the table row, except the spectrum, as a dictionary.

[Malte Marquarding]

This might not be possible as it relies on Mark Calabretta's livedata io library to provide access to all of these.