Add river routing module for offline (GEOSldas) simulations #2004

Job	Run time
build_gcm (ifort, Debug) / setup	2s
build_gcm (gfortran-15, Debug) / setup	3s
build_gcm (gfortran-14, Debug) / setup	3s
spack_build / Spack Build (ESMF stable)	34m 13s
build_gcm (ifort, Debug) / Build GEOS-ESM/GEOSgcm (ifort)	19m 22s
build_gcm (gfortran-15, Debug) / Build GEOS-ESM/GEOSgcm (gfortran-15)	34m 23s
build_gcm (gfortran-14, Debug) / Build GEOS-ESM/GEOSgcm (gfortran-14)	33m 2s
	2h 1m 8s

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