Create ioda2nc tool for IODA obs file format.

[dwfncar]

Interface for Observation Data Access (IODA) is the subsystem in the Joint Effort for Data assimilation Integration (JEDI) that provides access to observation data.
IODA uses an intermediate file format (NetCDF4) for all observation data
(surface stations, radiosonde, aircraft, satellite).
Python script converters to IODA NC4 exist in this repository (e.g. prepbufr to IODA):
https://github.com/JCSDA/ioda-converters.
ioda2nc should convert IODA NC4 to MET NC4, similar to ascii2nc tool.

Sample IODA nc header:
netcdf sondes_obs_2018041421_m {
dimensions:
nlocs = 131 ;
Station_ID_maxstrlen = 8 ;
Observation_Class_maxstrlen = 7 ;
nvars = 4 ;
nrecs = 4 ;
nobs = 524 ;
variables:
char station_id@MetaData(nlocs, Station_ID_maxstrlen) ;
int air_temperature@ObsType(nlocs) ;
float latitude@MetaData(nlocs) ;
float longitude@MetaData(nlocs) ;
float station_elevation@MetaData(nlocs) ;
float air_pressure@MetaData(nlocs) ;
float height@MetaData(nlocs) ;
float time@MetaData(nlocs) ;
float air_temperature@PreQC(nlocs) ;
float air_temperature@PreUseFlag(nlocs) ;
float air_temperature@GsiUseFlag(nlocs) ;
float air_temperature@GsiQCWeight(nlocs) ;
float air_temperature@ObsError(nlocs) ;
float air_temperature@GsiAdjustObsError(nlocs) ;
float air_temperature@GsiFinalObsError(nlocs) ;
float air_temperature@ObsValue(nlocs) ;
float air_temperature@GsiHofXBc(nlocs) ;
float air_temperature@GsiHofX(nlocs) ;
int specific_humidity@ObsType(nlocs) ;
float specific_humidity@PreQC(nlocs) ;
float specific_humidity@PreUseFlag(nlocs) ;
float specific_humidity@GsiQCWeight(nlocs) ;
float specific_humidity@GsiUseFlag(nlocs) ;
float specific_humidity@ObsError(nlocs) ;
float specific_humidity@GsiAdjustObsError(nlocs) ;
float specific_humidity@GsiFinalObsError(nlocs) ;
float specific_humidity@ObsValue(nlocs) ;
float specific_humidity@GsiHofXBc(nlocs) ;
float specific_humidity@GsiHofX(nlocs) ;
int eastward_wind@ObsType(nlocs) ;
int northward_wind@ObsType(nlocs) ;
float eastward_wind@PreQC(nlocs) ;
float northward_wind@PreQC(nlocs) ;
float eastward_wind@PreUseFlag(nlocs) ;
float northward_wind@PreUseFlag(nlocs) ;
float eastward_wind@GsiUseFlag(nlocs) ;
float northward_wind@GsiUseFlag(nlocs) ;
float eastward_wind@GsiQCWeight(nlocs) ;
float northward_wind@GsiQCWeight(nlocs) ;
float eastward_wind@ObsError(nlocs) ;
float northward_wind@ObsError(nlocs) ;
float eastward_wind@GsiAdjustObsError(nlocs) ;
float northward_wind@GsiAdjustObsError(nlocs) ;
float eastward_wind@GsiFinalObsError(nlocs) ;
float northward_wind@GsiFinalObsError(nlocs) ;
float gsi_wind_red_factor@MetaData(nlocs) ;
float eastward_wind@ObsValue(nlocs) ;
float eastward_wind@GsiHofXBc(nlocs) ;
float eastward_wind@GsiHofX(nlocs) ;
float northward_wind@ObsValue(nlocs) ;
float northward_wind@GsiHofXBc(nlocs) ;
float northward_wind@GsiHofX(nlocs) ;

// global attributes:
:date_time = 2018041500 ;
:nvars = 4LL ;
}

[dwfncar]

Placed sample IODA NC4 files on dakota:/d3/projects/MET/MET_IODA_development.

[dwfncar]

This issue is a duplicate of #1355

[dwfncar]

This issue is a duplicate of #1355