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

tests/pio_write.c

@@ -22,6 +22,7 @@
 #endif
 
 #include "cdi.h"
+#include "error.h"
 #include "dmemory.h"
 #include "pio_write.h"
 #ifdef USE_MPI
@@ -73,6 +74,8 @@ static const struct
   { "ieg", CDI_FILETYPE_IEG, CDI_DATATYPE_FLT64, GRID_LONLAT },
 };
 
+static void invalidOptionDie(const char *format, ...) __attribute__((noreturn));
+
 static void
 invalidOptionDie(const char *format, ...)
 {