Improved reading tables from GWOSC
This PR improves the parsing of open-data catalog event tables from GWOSC, mainly by detecting and replacing the 'NA'
that GWOSC uses to mark missing data. The logic here is a bit more complicated, because we have to determine the underlying data type of the column without the missing values, in order to replace the 'NA'
with the appropriate null value (0
for int
, nan
for float).