Format namelists correctly

[penguian]

See ACCESS-NRI/access-esm1.6-configs#213 (comment) Namelists should be formatted correctly, if at all possible. The run_radiation namelist for greenhouse gases is a priority. See also issue #47

[penguian]

@MartinDix
It turns out that correctly formatting a single namelist with f90nml is very tricky. There are two problems:

1. The main problem is a known issue in f90nml: patch() does not preserve formatting attributes (e.g. end_comma, float_format, indent, logical_repr, uppercase). Only write() preserves formatting attributes.
2. Using write() affects the whole namelist file, and therefore the result of write() has a single consistent value for each of the formatting attributes. See (e.g.) this diff where the old branch has varied formatting but the new branch has consistent f90nml formatting. The consistent formatting obtained through write() is usually not what is wanted when a namelist file is updated to change forcing values.

[penguian]

I have created a new suite u-dt074 that uses f90nml to reformat a single namelist file.

This helped me to discover a bug with f90nml: marshallward/f90nml#179 "A single null value should not be repeated." The bug affects the formatting of atmosphere/namelists so I will wait until it is fixed to try again.

[penguian]

See also ACCESS-NRI/access-esm1.6-configs#230

[penguian]

See marshallward/f90nml#180
and ACCESS-NRI/ACCESS-Analysis-Conda#330