Convert 10 day iodef.xml file to 1 month

The latest iodef.xml can be found from the link on the left, under the directory all_cmip_variables. Currently I get this ORCA1 version of this file by

fcm checkout fcm:moci.xm_br/dev/malcolmroberts/r1191_iodef_for_cmip6/iodef/all_cmip6_variables

and then delete the ORCA025 and directory which I don't want (it's not ideal, but I've not found a quicker way yet).

I think I'll need most of the changes that Tim Graham has made in modifying iodef.xml for u-ai737 between revision 30,303 and 30,858.

Instructions look to be

• Remove the two strings `split_freq="10d"'.
• 'file_group id="10d"' needs replacing with 'file_group id="1m"'. And the comment on this line should replace `10d files' with `1m files'.
• Replace `"10d"' by `"1mo"'
• The entry 'file_group id="1m"' lower down in file now needs removing.
• And finally, we probably want "using_server" set to false and "using_oasis" set to true for our setup.

For u-aj659, I think I've made the relevant changes in one go.