[#224] Add IATIProjectResource.benchmarks and IATIProjectResource.categories
[#224] Add IATIProjectResource.benchmarks and
IATIProjectResource.categories

Add new toManyFields to IATIBenchmarkResource and IATICategoryResource

Extend alter_deserialized_detail_data() to massage the data needed for
the new fields

akvo/akvo-rsr,akvo/akvo-rsr,akvo/akvo-rsr,akvo/akvo-rsr