[NCO Bug] Improve the COMIN path setting and clean up unused paths in gfs wave scripts

[KateFriedman-NOAA]

Bugzilla #1227

Details in bugzilla from NCO:

In the gfs wave scripts, the setting for COMIN path for rtofs is kind of confusing:
In jobs/JGLOBAL_WAVE_PREP
export COMIN_WAV_RTOFS=${COMIN_WAV_RTOFS:-$(compath.py ${WAVECUR_DID}/prod)}

However the $WAVECUR_DID is set in parm/config.wave

It should be more straightforward to use "rtofs" to replace the $WAVECUR_DID in the job script. Also according to implementation standard for upstream COMIN path varaible name, it should be better to use COMINrtofs instead of COMIN_WAV_RTOFS

In the other wave scripts, the $COMROOTp2 is still used, even though those input is no longer used, but it causes confustion:
JGLOBAL_WAVE_POST_BNDPNT:export COMIN_WAV_CUR=${COMIN_WAV_CUR:-${COMROOTp2}/rtofs/prod}
JGLOBAL_WAVE_POST_PNT:export COMIN_WAV_CUR=${COMIN_WAV_CUR:-${COMROOTp2}/rtofs/prod}
JGLOBAL_WAVE_POST_SBS:export COMIN_WAV_CUR=${COMIN_WAV_CUR:-${COMROOTp2}/rtofs/prod}
JGLOBAL_WAVE_POST_BNDPNT:export COMINice=${COMINice:-${COMROOTp2}/omb/prod}
JGLOBAL_WAVE_POST_PNT:export COMINice=${COMINice:-${COMROOTp2}/omb/prod}
JGLOBAL_WAVE_POST_SBS:export COMINice=${COMINice:-${COMROOTp2}/omb/prod}

The following are not used either:
JGLOBAL_WAVE_POST_BNDPNT:export COMINwnd=${COMINwnd:-${COMROOT}/gfs/prod}
JGLOBAL_WAVE_POST_PNT:export COMINwnd=${COMINwnd:-${COMROOT}/gfs/prod}
JGLOBAL_WAVE_POST_SBS:export COMINwnd=${COMINwnd:-${COMROOT}/gfs/prod}

Please clean up all those pathes. 

It can be improved in next upgrade.