Add mpirun flag to prepend rank

- added "-l" flag to mpirun command to prepend/insert the MPI process rank
at the beginning of all lines written to the standard output
- was tested in operations while investigating GFS ops failures
- include flag moving forward in operational system, starting with v16.1.5

Refs: #439

env/WCOSS_DELL_P3.env

@@ -14,7 +14,7 @@ fi
 step=$1
 
 # WCOSS_DELL_P3 information
-export launcher="mpirun -n"
+export launcher="mpirun -l -n"
 export mpmd="cfp"
 
 export npe_node_max=28