transition from F77 to F90 for NetCDF in utilitaries

[lrossi]

The use of F77 calls for NetCDF functions leads to some conflicts between compilers regarding the function calls.

This comes from the fact that gfortran 10+ wants one-elements arrays instead of scalars when calling netCDF routines (cf. revisions r2567 and r2577). This has lead to changes in the calls
e.g.

miss=NF_GET_ATT_REAL(nid,varid,"missing_value",missing)

becomes

miss=NF_GET_ATT_REAL(nid,varid,"missing_value",[missing])

But while this compiles ok when using ifort, these changes introduce wrong values (typically missing_values being read incorrectly).

A likely fix would be to transition to NetCDF F77 interface to F90 interface.