Add river routing module for offline (GEOSldas) simulations #1981

Job	Run time
build_gcm (ifort, Debug) / setup	3s
build_gcm (gfortran-14, Debug) / setup	3s
spack_build / Spack Build (ESMF stable)	35m 36s
build_gcm (gfortran-15, Debug) / setup	3s
build_gcm (gfortran-15, Debug) / Build GEOS-ESM/GEOSgcm (gfortran-15)	34m 15s
build_gcm (ifort, Debug) / Build GEOS-ESM/GEOSgcm (ifort)	19m 49s
build_gcm (gfortran-14, Debug) / Build GEOS-ESM/GEOSgcm (gfortran-14)	33m 32s
	2h 3m 21s

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