Customizing error messages in global onError callback.
Very often I would like to curate the messages shown in a globally configured toast message that is dispatched by a global onError or onSuccess callback on a per mutation basis. For example, a confirmation message could say
Successfully created [name_of_thing] where [name_of_thing] comes from the mutation response. In the case of an error, [name_of_thing] may need to come from local state if the network request fails. I can't use the meta
