This adds scripts for generating the C API bindings from template files,
while also generating bigcount interfaces for those that require them.
The binding script also include initial support for the mpi_f08 Fortran
bindings, but doesn't yet make any changes to fortran/use-mpi-f08

Python >=3.6 is required for running these scripts, which is only
necessary when the binding files have not already been generated.
Users of the distribution tarball should not need to generate these
files and thus should not require Python.

Co-authored-by: mphinney1100 <[email protected]>
Co-authored-by: Howard Pritchard <[email protected]>
Signed-off-by: Jake Tronge <[email protected]>

This updates fortran/use-mpi-f08 to generate most of the Fortran
bindings from a script and template files. It also adds support for
Fortran TS 29113 when possible, allowing for better Fortran array
handling that matches the standard.

The C files were imported from PR open-mpi#10302 and converted to templates to
be fed into the binding script.

Co-authored-by: Gilles Gouaillardet <[email protected]>
Co-authored-by: Howard Pritchard <[email protected]>
Signed-off-by: Jake Tronge <[email protected]>