[GPU Porting] MOM_io.F90

[edoyango]

access-om3:

• create_mom_file (2.13s)
• query_vardesc (0.19s)
• set_axis_info (0.08s)
• mom_read_data_2d (0.08s)
• var_desc (0.07s)
• mom_read_data_3d_region (0.04s)
• modify_vardesc (0.04s)
• read_attribute_real (0.04s)
• safe_string_copy (0.02s)
• read_netcdf_data_2d (0.01s)
• mom_write_field_3d (0.01s)
• open_namelist_file (0.01s)
• get_var_axes_info (0.01s)
• mom_io_init (0.01s)

most of these probably aren't appropriate for porting, but need to confirm

Originally opened by @edoyango in marshallward/MOM6#139 (https://github.com/marshallward/MOM6/issues/139).
Original labels not available on this repo: gpu, ACCESS-OM3 config.