Migrate a Pipedrive integration from API v1 to v2

Steps

1. Replace offset-based pagination (start & limit) with cursor-based pagination (cursor & limit) across Products, Deals, Persons, Organizations, Pipelines, and Stages endpoints.
2. Update custom field handling: v1 exposed custom fields as root-level keys like "{hash}" and "{hash}_currency"; v2 nests them under a custom_fields object, e.g. "custom_fields": {"{hash}": {"value": 2300, "currency": "EUR"}}.
3. Apply the same nested restructuring to other custom field types (text, numeric, currency, address) where v1 used suffixed root keys (e.g. _route, _locality, _postal_code) and v2 nests them as sub-objects.
4. Update pagination-following logic to read the returned cursor value and pass it back in as the next request's cursor parameter instead of incrementing an offset.