convert-from-ocds: add location ids in transform

[pindec]

The project location transform currently doesn't add any id fields, so the OC4IDS DRT reports a structural error on output with locations since id is required.

• From OCDS, location is inferred from any existing item/deliveryLocation fields from the Location extension. Since there is only one deliveryLocation per item, there are no id fields in source data, but there may be multiple items with a deliveryLocation within a tender in source OCDS data.
• From OCDS for PPPs, location objects are copied from /planning/project/locations from the Projects extension, which also don't haveid fields.

The conversion script should generate location ids.

Related issue on adding more tests for location: #3