Consolidation with CDI-PIO (develop)

Generally, this is !11 (merged) rebased onto the develop branch.

This is the first develop-based version accepted by the Buildbot of ICON: https://buildbot.dkrz.de/grid?branch=m300488/cdi-pio-2-integration

src/pkgconfig/cdipio.pc.in

@@ -4,7 +4,7 @@ libdir=@libdir@
 includedir=@includedir@
 cflags=-I@includedir@
 fcflags=@FPP_INCOPT@@includedir@ @CDI_F90_INTERFACE_FCFLAGS@
-libs=-L@libdir@ -lcdipio @LIBRT@ @PPM_CORE_LIBS@ @YAXT_C_LIB@ @MPI_C_LIB@ -lcdi @GRIB_API_LIBS@ @NETCDF_LIBS@ @SZLIB_LIBS@ @THREADS_LIBS@ @LIBS@
+libs=-L@libdir@ -lcdipio @LIBRT@ @PPM_CORE_C_LIB@ @YAXT_C_LIB@ @MPI_C_LIB@ -lcdi @GRIB_API_LIBS@ @NETCDF_LIBS@ @SZLIB_LIBS@ @THREADS_LIBS@ @LIBS@
 threads_libs=@THREADS_LIBS@
 threads_cflags=@THREADS_INCLUDE@
 szlib_cflags=@SZLIB_INCLUDE@