Use new ecCodes function to determine if descriptor is coordinate

[iainrussell]

What maintenance does this project need?

eccodes-python 1.6.0 will introduce a new function, codes_bufr_key_is_coordinate(msgid, key) (https://jira.ecmwf.int/browse/ECC-1611) which pdbufr should use to replace its own code. Let's wait until that version of eccodes-python has been released for a bit before making it a dependency.

Organisation

ECMWF

[sandorkertesz]

Please note that codes_bufr_key_is_coordinate uses a different algorithm than pdbufr to decide if a key is a coordinate and for certain keys they disagree. This should also taken into account before making this change.

[shahramn]

See https://confluence.ecmwf.int/display/UDOC/What+are+coordinate+descriptors+-+ecCodes+BUFR+FAQ